Had Unprotected Sex? What to Do Next
A calm, practical timeline for emergency contraception, HIV PEP, STI testing, pregnancy testing, symptoms, condom failure, and the decisions that actually matter.
Start with the clock, not with symptoms. After unprotected sex, the first questions are whether pregnancy is possible, whether the encounter could justify HIV PEP, whether a condom failed, and whether you need STI testing at the correct time.
HIV PEP must be started within 72 hours of a possible exposure. Emergency contraception must usually be used within three to five days, depending on the method. Both work best when action is taken quickly.
Testing immediately after sex usually cannot rule out an infection acquired during that encounter. Different infections and different tests have different window periods. Testing too early may give you a result that does not yet cover the recent exposure.
High-standards call: handle the time-sensitive decisions first, then build the testing plan. Do not spend the urgent window checking your throat, skin, tongue, temperature, or lymph nodes.
Inside 72 hours and concerned about possible HIV exposure? Contact a sexual health clinic, doctor, urgent care service, or emergency department immediately for a PEP assessment. In the UK, PEP is available through sexual health clinics and A&E.
The timeline after unprotected sex
Unprotected sex can create several separate questions. Pregnancy prevention, HIV prevention, bacterial STI testing, HIV testing, and symptom assessment do not all run on the same clock.
Work out what actually happened. Identify the type of sex, whether a condom was used, whether it broke or slipped, whether semen could have entered the vagina, and whether there was blood, injury, or non-consensual contact.
Seek an urgent HIV PEP assessment if there was a meaningful possible exposure. Levonorgestrel emergency contraception must also generally be taken within 72 hours.
Ulipristal acetate emergency contraception can be used within 120 hours, and a copper IUD may also be an option. Do not assume the window has closed just because more than three days have passed.
Many UK sexual health services use approximately two weeks as the window for chlamydia and gonorrhea testing. Earlier testing may be recommended if symptoms appear or a partner has received a diagnosis.
If pregnancy is possible and you do not know when the next period is due, an NHS-supported rule is to take a pregnancy test at least 21 days after the last unprotected sex.
A laboratory antigen and antibody HIV test using blood from a vein can usually detect infection within 18 to 45 days. The exact advice depends on the test used and whether PEP or PrEP was involved.
Some services advise a longer window for syphilis and for antibody-only HIV tests, including many rapid or oral self-tests. Follow the window supplied with your specific test.
Testing windows vary by service, test technology, treatment history, and individual circumstances. Use the instructions provided by your clinic or test manufacturer.
What counts as unprotected sex?
Unprotected sex usually means vaginal or anal penetration without a condom. However, it can also include an encounter where protection was intended but the barrier did not protect the entire act.
No effective barrier
- Vaginal or anal sex without a condom.
- A condom that visibly broke or tore.
- A condom that slipped off during penetration.
- Penetration before the condom was applied.
- Penetration after the condom was removed.
- A contraceptive failure that could allow pregnancy.
Not every sexual act carries the same risks
- Oral sex does not create pregnancy risk.
- Oral sex has a much lower HIV risk than vaginal or anal sex.
- Some bacterial STIs can spread through oral sex.
- Skin-to-skin infections can spread despite condom use.
- An intact condom changes the HIV and pregnancy assessment substantially.
The label alone does not tell you how risky the encounter was. The biological route matters. Receptive anal sex, insertive vaginal sex, receiving oral sex, and genital touching are not interchangeable exposures.
What to do immediately after unprotected sex
Write down what happened
Record the date and approximate time, type of sex, your role, condom use, ejaculation, contraception, PrEP use, known partner information, and whether blood or visible injury was present.
Check the urgent windows
Decide whether pregnancy prevention or an HIV PEP assessment could be needed. These decisions cannot wait for symptoms or for a test to become accurate.
Use normal external hygiene
You can wash normally for comfort, but do not scrub aggressively or put bleach, disinfectant, soap, antiseptic, or other chemicals inside the vagina, rectum, or urethra.
Contact the right service
A sexual health clinic can assess STI testing, emergency contraception, HIV PEP, symptoms, and exposed body sites. You usually do not need to wait for a GP referral.
Urinating, showering, douching, or washing the genitals after sex does not remove an STI that has already entered susceptible tissue. It also does not reliably prevent pregnancy.
Internal washing may irritate tissue and create additional discomfort, which can then trigger more symptom anxiety.
Within 72 hours: should you ask about HIV PEP?
PEP stands for post-exposure prophylaxis. It is a course of HIV medicine used after a possible exposure to reduce the chance of infection.
PEP must be started within 72 hours and should be started as soon as possible. It is not automatically prescribed after every sexual encounter. A clinician considers the sex act, your role, condom failure, the partner's HIV status or likelihood, viral suppression, PrEP use, and other exposure details.
Higher-concern routes
Condomless receptive anal or vaginal sex, meaningful condom failure, or direct exposure to potentially infectious blood or genital fluid may justify urgent assessment.
Status and viral load matter
Concern is greater if the partner is known to have HIV and is not confirmed virally suppressed. A sustained undetectable viral load prevents sexual HIV transmission.
PEP is not for every fear
Intact-condom sex, receiving oral sex, touching, kissing, and everyday contact generally do not create the same HIV exposure pathway.
Do not wait until hour 70 to begin looking for help. If a plausible HIV exposure happened within the last 72 hours, contact a sexual health service or emergency provider now. The clinical decision can be made after you reach care.
For a detailed explanation of how clinicians evaluate different encounters, read when HIV PEP is recommended.
Within five days: emergency contraception
Emergency contraception may be relevant when sperm could have entered the vagina and pregnancy is possible. It does not prevent HIV or other STIs.
| Method | Typical time limit | Important point |
|---|---|---|
| Levonorgestrel emergency pill | Within 72 hours | It should be taken as soon as possible. Suitability can depend on medication use, weight, and other factors. |
| Ulipristal acetate emergency pill | Within 120 hours | It may be an option up to five days after sex. A pharmacist or clinician can advise whether it is suitable. |
| Copper intrauterine device | Usually within five days | The copper IUD is the most effective form of emergency contraception and can continue to provide contraception afterward. |
NHS guidance states that emergency contraception needs to be used within three to five days, depending on the method, and that it is usually more effective when used sooner.
A pharmacist, contraception clinic, sexual health clinic, GP, or other qualified service can help identify the most appropriate option. Do not exclude yourself based only on something you read online.
When should you test for STIs?
There is no single universal "STI test." Different infections require different samples and become detectable at different times.
| Infection or concern | Common testing point | Usual sample |
|---|---|---|
| Chlamydia | Many UK services advise around two weeks | Urine or genital, throat, or rectal swab depending on exposure |
| Gonorrhea | Many UK services advise around two weeks | Urine or genital, throat, or rectal swab depending on exposure |
| HIV laboratory antigen and antibody test | Usually detects infection within 18 to 45 days | Blood from a vein |
| HIV rapid or antibody-only test | May require up to 90 days | Finger-stick blood or oral fluid, depending on test |
| Syphilis | Some UK services advise up to 12 weeks | Blood test, with lesion testing when appropriate |
| Pregnancy | From the first missed period or at least 21 days if the period date is unknown | Urine pregnancy test |
These are general guideposts, not a substitute for the instructions from your test provider. Testing advice may change if you took PEP, use PrEP, have symptoms, are pregnant, or have a weakened immune system.
For a deeper breakdown of HIV blood tests, rapid tests, and oral tests, read HIV testing window periods.
Make sure the correct body sites are tested
A urine sample alone may not test every exposed area. Tell the clinic whether the encounter involved oral, vaginal, or anal sex and whether you were the insertive or receptive partner.
Urine or genital swab
These samples may detect infections affecting the urethra, vagina, or cervix. The specific sample depends on anatomy and the service used.
Throat swab
Gonorrhea and some other infections can affect the throat without obvious symptoms. A urine test does not rule out a throat infection.
Rectal swab
A rectal infection can exist even when urine testing is negative. Tell the service where exposure occurred so testing matches the encounter.
When should you take a pregnancy test?
Most pregnancy tests can be used from the first day of a missed period. If you do not know when the next period is due, NHS guidance recommends testing at least 21 days after the last unprotected sex.
A test taken only a few days after sex is usually too early to rule out pregnancy from that encounter. An early negative result may need to be repeated at the correct time.
Pregnancy is possible when sperm can enter the vagina and reach an egg. Oral sex, anal sex without semen reaching the vulva or vagina, kissing, touching, and semen on intact external skin do not create the same pregnancy pathway.
What if symptoms appear before the testing window?
Do not wait for the full routine testing window if you develop symptoms or if a partner tells you they tested positive for an STI. Contact a sexual health clinic for advice.
Contact a clinic
- Unusual genital discharge.
- Burning or pain when urinating.
- Genital, anal, or mouth ulcers.
- New blisters or sores.
- Pelvic pain or pain during sex.
- Testicular pain or swelling.
- Rectal pain, discharge, or bleeding.
- A widespread unexplained rash.
Symptoms cannot identify the infection
Many STIs cause no symptoms. When symptoms do occur, they often overlap with urinary infections, yeast infections, bacterial vaginosis, irritation, allergies, ordinary viral illnesses, and unrelated skin conditions.
Symptoms can justify medical assessment, but they cannot replace testing.
Seek urgent medical care for severe pelvic or abdominal pain, heavy bleeding, fainting, serious testicular pain, rapidly worsening swelling, major injury, or signs of a severe allergic reaction.
What if the condom broke or slipped off?
A condom failure should be reviewed based on the part of the encounter that became unprotected. A condom that shifted slightly but continued covering the penis is different from one that came off completely while penetration continued.
No meaningful loss of protection
The condom remained on, continued to cover the penis, did not visibly tear, and penetration did not continue without protection.
Actual unprotected contact
The condom broke, came off, was applied late, was removed early, or allowed semen or genital fluid to contact vulnerable tissue during penetration.
Read the complete guide to condom breakage, slippage, protected sex, and HIV risk.
Pregnancy, HIV, and other STIs are different questions
Can sperm reach the vagina?
Pregnancy prevention matters when semen or sperm-containing fluid may have entered the vagina. The partner's STI or HIV status does not determine pregnancy risk.
Was there a realistic transmission route?
HIV risk depends heavily on the sex act, role, barrier use, partner status, viral load, PrEP, PEP timing, and whether infectious fluid reached susceptible tissue.
What sites were exposed?
Chlamydia, gonorrhea, syphilis, herpes, HPV, and other infections have different transmission routes. Some can spread through oral or skin-to-skin contact.
What if the partner says they are clean or recently tested?
A partner's recent negative results can be useful information, but the details matter. Ask what infections they were tested for, when testing occurred, whether they had any exposures afterward, and whether the tests were outside the relevant window periods.
Avoid the word "clean." People with an STI are not dirty, and many infections are common, treatable, and asymptomatic.
A partner's reassurance should not replace urgent action when emergency contraception or HIV PEP may be time-sensitive. You can clarify their information while also contacting a healthcare service.
What if you were taking PrEP?
Correctly used PrEP is highly effective at preventing sexual acquisition of HIV. However, it does not prevent pregnancy, chlamydia, gonorrhea, syphilis, herpes, HPV, or most other STIs.
Tell the clinician which PrEP method you use, when you started, whether doses were missed, and when the exposure happened. People who took PrEP as prescribed will often not need PEP, but missed or delayed doses can change the assessment.
What if the sex was not consensual?
If you were assaulted, pressured, unable to consent, or injured, you deserve confidential medical and practical support. You can seek care without deciding immediately whether to report the incident to police.
Sexual assault referral centres can provide crisis support, medical care, emergency contraception, STI testing, and forensic examination where appropriate.
Your immediate safety comes first. In the UK, you can find a sexual assault referral centre through the NHS. If you are in immediate danger or have a life-threatening injury, contact emergency services.
Common mistakes after unprotected sex
Waiting for symptoms before acting
PEP and emergency contraception operate on short time limits. Symptoms usually cannot tell you whether either intervention is needed.
Testing the next morning
A negative test immediately after sex may describe your status before the encounter, but it generally cannot exclude an infection acquired during that recent encounter.
Taking leftover antibiotics
Random antibiotics may not treat the correct infection, may interfere with assessment, can cause side effects, and contribute to antibiotic resistance.
Testing only urine
Urine testing may miss infections in the throat or rectum. Samples should reflect every body site exposed during sex.
Treating every symptom as HIV
A sore throat, fatigue, rash, swollen gland, headache, or stomach problem is not specific enough to diagnose acute HIV.
Assuming every encounter is equally risky
The act, role, barrier, partner viral load, PrEP use, and fluid exposure matter. Risk cannot be judged from anxiety intensity alone.
A simple action plan
Review
Write down the act, timing, condom use, contraception, ejaculation, body sites, and known partner information.
Protect
Seek emergency contraception within three to five days and HIV PEP assessment within 72 hours when relevant.
Test
Use the correct STI, HIV, and pregnancy windows. Make sure every exposed body site is included.
Prevent
Consider condoms, contraception, PrEP, vaccines, routine screening, and a plan for future condom failures.
Unprotected sex does not produce one universal HIV risk. The estimate changes according to the act, your role, partner context, country, condom use, ejaculation, PrEP, circumcision, treatment status, and other exposure details.
HIVRISKREPORT creates a private, evidence-based analysis of a single encounter, including a statistical risk estimate, the factors driving it, and clear next steps for testing.
Get My Confidential Risk ReportWhen should you contact a sexual health clinic?
- You may need HIV PEP and the encounter occurred within 72 hours.
- Pregnancy is possible and the encounter occurred within the emergency contraception window.
- A partner has tested positive for an STI.
- You have discharge, sores, pain, burning, bleeding, or other symptoms.
- You need throat or rectal testing that is not included in a home kit.
- You took PEP or use PrEP and need a tailored HIV testing schedule.
- The encounter was non-consensual or involved injury.
- You are uncertain what tests you need or when they will be reliable.
Frequently Asked Questions
Check whether pregnancy, HIV, or another STI is realistically possible. Do not douche or use chemicals internally. Seek urgent advice if emergency contraception, HIV PEP, care after sexual assault, or treatment for an injury may be needed.
PEP must be started within 72 hours and should be started as soon as possible. A clinician must assess whether the exposure meets the criteria for treatment.
Emergency contraception must generally be used within three to five days, depending on the method. The sooner it is used, the more effective it usually is.
Many UK sexual health services advise testing from around two weeks after exposure. Contact a clinic sooner if you develop symptoms or a partner has tested positive.
Most tests can be used from the first day of a missed period. If you do not know when the next period is due, test at least 21 days after the unprotected sex.
No. Many STIs cause no symptoms, and symptoms such as discharge, irritation, sore throat, rash, or burning can have several possible causes. Testing and clinical assessment are more reliable.
No. Washing, urinating, or douching does not remove an infection or reliably prevent pregnancy. Internal cleaning may also irritate vulnerable tissue.
Possibly. Testing should match the sites exposed during sex. Oral exposure may require a throat swab, and receptive anal exposure may require a rectal swab.
No. Different infections require different samples. A full screen may involve urine, genital swabs, throat or rectal swabs, and blood tests.
Using condoms or avoiding sexual contact can reduce the chance of passing on a possible infection. If you have symptoms, a diagnosed infection, or specific clinic instructions, follow the healthcare provider's advice before resuming sex.
Sources and References
- NHS, Emergency contraception: nhs.uk/contraception/emergency-contraception
- NHS, How to take the emergency contraceptive pill: nhs.uk/.../how-to-take-it
- NHS, Doing a pregnancy test: nhs.uk/pregnancy/.../doing-a-pregnancy-test
- CDC, Preventing HIV with PEP: cdc.gov/hiv/prevention/pep
- CDC, Clinical Guidance for PEP: cdc.gov/hivnexus/hcp/pep
- CDC, Getting Tested for HIV: cdc.gov/hiv/testing
- NHS, HIV and AIDS: nhs.uk/conditions/hiv-and-aids
- NHS, Sexually transmitted infections: nhs.uk/conditions/sexually-transmitted-infections-stis
- NHS, Visiting a sexual health clinic: nhs.uk/.../visiting-an-sti-clinic
- CDC, Getting Tested for STIs: cdc.gov/sti/testing
- NHS, Find STI testing and treatment: nhs.uk/.../find-sti-testing-and-treatment
- NHS, Find a rape and sexual assault referral centre: nhs.uk/.../find-a-rape-and-sexual-assault-referral-centre
This article is for education and general decision support. It does not diagnose an STI, determine whether you are pregnant, or replace personal medical advice.
If a possible HIV exposure occurred within the last 72 hours, pregnancy is possible within the emergency contraception window, you have severe symptoms, or the encounter was non-consensual, contact an appropriate healthcare service promptly.
Knowing the facts, acting within the correct window, and using properly timed testing can help curb anxiety and replace uncertainty with a clear plan.