The most important thing right now is that some protective steps are time-sensitive, so acting within the first 24 to 72 hours makes a real difference. Whether you’re concerned about pregnancy, STIs, or both, here’s what to do and when.
Don’t Douche or Over-Clean
Your first instinct might be to wash thoroughly or douche, but this can actually make things worse. Douching disrupts the balance of protective bacteria in the vagina and increases the risk of bacterial vaginosis and other infections. Women who douche weekly are five times more likely to develop BV than those who don’t. If bacteria were introduced during sex, douching can push them deeper into the reproductive tract, potentially causing pelvic inflammatory disease. A normal shower is fine. Let your body’s natural defenses do their job.
Emergency Contraception: Your Options and Deadlines
If pregnancy is a concern, you have three options, and timing matters for each one.
The most widely available option is the levonorgestrel pill (sold as Plan B and generics), which you can buy over the counter at most pharmacies. It works best when taken as soon as possible and is approved for use within 72 hours of unprotected sex. Waiting matters: taking it on day five instead of day one increases the risk of pregnancy almost sixfold, at which point it performs no better than a placebo.
A second pill option, ulipristal acetate (sold as ella), is effective for up to 120 hours (five days) after sex and, unlike levonorgestrel, does not lose effectiveness over that window. It requires a prescription in the U.S., but some telehealth services can provide one quickly. If you’re past the 72-hour mark, this is the better oral option.
The most effective emergency contraceptive is a copper IUD, with a failure rate below 0.2%. A healthcare provider needs to place it, but if you can get an appointment within five days, it offers the strongest protection against pregnancy and doubles as long-term birth control going forward.
HIV Prevention: The 72-Hour Window for PEP
Post-exposure prophylaxis, or PEP, is a course of HIV medication that can prevent infection after a potential exposure. It must be started within 72 hours, and the sooner the better. You’ll take the medication daily for 28 days.
PEP is available through emergency rooms, urgent care clinics, sexual health clinics, and some primary care offices. If you’re unsure whether your encounter posed a meaningful HIV risk, a provider can help you assess that based on the type of sex, your partner’s likely status, and other factors. Not every encounter warrants PEP, but if you’re worried, don’t wait to ask. The clock is ticking on this one.
Bacterial STI Prevention With Doxy-PEP
A newer option for preventing bacterial STIs like chlamydia, gonorrhea, and syphilis is doxycycline post-exposure prophylaxis, or doxy-PEP. The CDC published clinical guidelines for this in 2024. The recommended dose is 200 mg of doxycycline taken as soon as possible after sex, within 72 hours at the latest. You should not exceed 200 mg in any 24-hour period.
Doxy-PEP requires a prescription. It’s primarily recommended for men who have sex with men and transgender women who have had a bacterial STI in the past year, but your provider can discuss whether it makes sense for your situation.
When to Get Tested for STIs
Getting tested the morning after won’t tell you anything useful. STIs need time to become detectable, and testing too early produces false negatives. Here’s when results become reliable:
- Gonorrhea: Test at least 2 weeks after exposure. Symptoms, if they appear at all, typically show up within 2 to 8 days, but many infections (especially vaginal) cause no symptoms.
- Chlamydia: Test at least 2 weeks after exposure. Symptoms take 1 to 3 weeks on average, but the majority of infections are asymptomatic.
- Syphilis: Test at least 3 to 4 weeks after exposure. A sore can appear anywhere from 10 to 90 days later, with 21 days being the average, and it’s often too mild to notice.
- HIV: A fourth-generation test is reliable at about 4 weeks after exposure, though some providers recommend confirming with a follow-up test at 3 months.
The key takeaway is that most bacterial STIs frequently produce no symptoms at all. You cannot rely on feeling fine as evidence that you’re in the clear. Testing is the only way to know.
When to Take a Pregnancy Test
A pregnancy test detects a hormone called hCG, which the body starts producing about six days after fertilization. But levels need time to build. The NHS recommends waiting at least 21 days after unprotected sex if you don’t know when your next period is due. If you do track your cycle, the first day of a missed period is the earliest reliable time to test. Some sensitive tests claim to work a few days before a missed period, but waiting gives you a more trustworthy result.
Finding Low-Cost Testing and Care
If cost or insurance is a barrier, Planned Parenthood offers sliding-scale pricing for STI testing, emergency contraception, and related services. Eligibility for reduced or no-cost care depends on income, household size, and local program availability. You can call 1-800-230-PLAN to ask about options. Many city and county health departments also offer free or low-cost STI testing, and some urgent care clinics can prescribe PEP on the spot.
If you’re uninsured, you may qualify for no-cost birth control and sexual health services through Title X-funded clinics. These visits are confidential.
What to Watch For in the Coming Weeks
Even without symptoms, plan on getting a full STI panel at the appropriate window periods listed above. In the meantime, pay attention to anything unusual: new discharge, burning during urination, sores or bumps in the genital area, pelvic pain, or a sore throat that doesn’t resolve (oral gonorrhea is often mistaken for a common infection). None of these symptoms are guaranteed to appear, and their absence doesn’t mean you’re negative. But if something does show up, it’s a signal to get tested sooner rather than later.