Had Unprotected Sex? Here Are Your Concrete Next Steps

Emergency contraception — how long do you have?

If pregnancy is a concern and you have a uterus, emergency contraception (EC) is an option. Two main types exist 1Ref 1American College of Obstetricians and Gynecologists (2015).Practice Bulletin No. 152: Emergency Contraception.Hormonal EC mechanism (ovulation delay), timing windows (72 hours / 120 hours), copper IUD as most effective EC option up to 5 days; EC does not end a pregnancy:

Hormonal EC pills (often called "the morning-after pill") work primarily by delaying ovulation. Most formulations are approved within 72 hours; some extend to 120 hours (5 days), though effectiveness decreases over time. Hormonal EC does not end a pregnancy — it works before implantation.

Copper IUD is the most effective form of EC (over 99%) and can be inserted by a clinician up to 5 days after unprotected sex. It then serves as ongoing long-term contraception. This requires a same-day or next-day appointment, so acting quickly matters.

Body weight can affect the effectiveness of some oral EC options; a clinician or pharmacist can advise on the best choice. EC does not protect against STIs 1Ref 1American College of Obstetricians and Gynecologists (2015).Practice Bulletin No. 152: Emergency Contraception.Hormonal EC mechanism (ovulation delay), timing windows (72 hours / 120 hours), copper IUD as most effective EC option up to 5 days; EC does not end a pregnancy.

HIV PEP — this has a hard 72-hour deadline

If there is a meaningful possibility that the other person was living with HIV — or if you do not know their status and the encounter was high-risk — HIV post-exposure prophylaxis (PEP) is worth considering urgently. PEP is a course of antiretroviral medications that significantly reduces the risk of HIV infection when started within 72 hours of potential exposure 2Ref 2Centers for Disease Control and Prevention (2021).Preexposure Prophylaxis for the Prevention of HIV Infection in the United States – 2021 Update: A Clinical Practice Guideline.PEP 72-hour deadline, high-risk exposure types, risk stratification informing PEP decisions, no longer recommended after 72 hours. After 72 hours, it is no longer recommended.

High-risk exposures include receptive anal sex without a condom, vaginal sex without a condom, or any encounter with a partner known to have HIV who is not virally suppressed. The CDC's PrEP/PEP clinical guidance covers the risk stratification that informs PEP decisions 2Ref 2Centers for Disease Control and Prevention (2021).Preexposure Prophylaxis for the Prevention of HIV Infection in the United States – 2021 Update: A Clinical Practice Guideline.PEP 72-hour deadline, high-risk exposure types, risk stratification informing PEP decisions, no longer recommended after 72 hours. Do not wait for symptoms — HIV rarely causes immediate symptoms.

If you are seeking PEP, contact a clinician, urgent care, or an emergency department today. Hormonal EC pills are available over the counter; PEP requires a prescription and may be available at low or no cost through health departments or community health centers.

STI testing — what to test for and when

Most STIs have a window period during which tests may not yet be accurate. Testing too early can give a false-negative result. General timing guidance 3Ref 3Workowski KA, Bachmann LH, Chan PA, Johnston CM, Muzny CA, Park I, Reno H, Zenilman JM, Bolan GA (2021).Sexually Transmitted Infections Treatment Guidelines, 2021.Chlamydia and gonorrhea NAAT testing approximately 2 weeks after exposure; STI window periods; herpes swab accuracy for active sores:

• Chlamydia and gonorrhea: detectable roughly 2 weeks after exposure. NAAT (nucleic acid amplification test) is the most sensitive test 3Ref 3Workowski KA, Bachmann LH, Chan PA, Johnston CM, Muzny CA, Park I, Reno H, Zenilman JM, Bolan GA (2021).Sexually Transmitted Infections Treatment Guidelines, 2021.Chlamydia and gonorrhea NAAT testing approximately 2 weeks after exposure; STI window periods; herpes swab accuracy for active sores.
• Syphilis: typically detectable at 3 to 6 weeks; full confirmation usually requires testing at 3 months 4Ref 4Centers for Disease Control and Prevention (2021).Syphilis — STI Treatment Guidelines 2021 (Web Chapter).Syphilis serological testing window: detectable at 3 to 6 weeks, confirmed at 3 months.
• HIV: combination antigen/antibody tests (the current standard) detect most infections within 18 to 45 days; a negative result at 45 days is considered reliable at most labs, confirmed at 3 months 5Ref 5US Preventive Services Task Force; Owens DK, Davidson KW, Krist AH, et al. (2019).Screening for HIV Infection: US Preventive Services Task Force Recommendation Statement.HIV combination antigen/antibody test as current standard; testing window and confirmation at 3 months context.
• Herpes: blood antibody tests are not reliably positive until weeks after a first infection and are not routinely recommended after a single exposure without symptoms. A swab of an active sore is far more accurate.
• Hepatitis B and C: windows vary; a clinician will advise based on your vaccination status and exposure type.

A telehealth visit is a good starting point for ordering the right panel if you have a regular clinician. Many sexual health clinics offer confidential testing without a referral.

What to do while you wait for results

Avoid sex with partners who do not know about the potential exposure until your results are back — to protect them and to avoid re-exposure before you have a result. You do not need to quarantine from daily life. Note any symptoms that develop: unusual discharge, genital sores, a rash (especially on the palms or soles), fever, or swollen lymph nodes. Report these to your clinician, as they may affect which tests are ordered or how urgently.