You generally need to wait around two weeks after sex (or until your period is late) before a home pregnancy test can reliably pick up a pregnancy.

Quick Scoop: Timing in Plain Terms

  • Not right away: A pregnancy test cannot tell you anything immediately after sex; the body needs time to produce the hormone hCG that tests detect.
  • Typical window: Most experts suggest waiting 10–14 days after unprotected sex , or testing from the first day your period is late for the most accurate result.
  • Best accuracy: Waiting about two weeks after the encounter or after a missed period gives the highest chance of a correct result with a home urine test.
  • Irregular periods: If your cycle is irregular or you’re unsure when your period is due, many clinicians recommend waiting 2–3 weeks after unprotected sex before testing.

Why you can’t test “right after” sex

Pregnancy doesn’t start at the exact moment you have sex.

  • It can take up to around 6 days for sperm to meet the egg and for a fertilized egg to form.
  • After that, it needs to implant in the uterus before your body starts making noticeable hCG (the hormone pregnancy tests look for).
  • This whole process is why most tests won’t be accurate until roughly two weeks after sex or when your period is late.

Think of hCG as the “signal” your test listens for; the signal simply isn’t strong enough right away.

Rough Timeline After Sex

Here’s a simple breakdown of what different time points mean.

  • Within 24 hours – 5 days after sex:
    • Too early for a pregnancy test to work.
* If you _don’t_ want to be pregnant, this is the window for **emergency contraception** , which works best in the first 3 days but can be used up to 5 days after unprotected sex.
  • About 5–7 days after sex:
    • Still usually too early for a reliable urine test; many pregnancies haven’t implanted yet.
* A negative result at this point doesn’t mean much.
  • About 10–14 days after sex:
    • Some early-detection tests may pick up pregnancy around here, especially closer to day 14.
* Many sources recommend this as the earliest “reasonable” time to test if you can’t wait for a missed period.
  • From the first day of a missed period (roughly 2 weeks after sex):
    • Most accurate time for a home test for many people with regular cycles.
* Accuracy increases if you wait up to a week after the missed period.
  • If periods are irregular or you don’t track them:
    • Aim for 2–3 weeks after unprotected sex for a more reliable result.
* If tests stay negative but you have pregnancy symptoms, talk to a clinician.

Extra Tips for More Accurate Results

  • Use first-morning urine: hCG is usually most concentrated in your first pee after waking, which can make tests more sensitive early on.
  • Follow the instructions exactly: Different brands have different wait times and ways to read the lines or digital display.
  • If you test early and it’s negative:
    • Wait a few days to a week and test again if your period still hasn’t come.
  • Blood tests: A blood test at a clinic can detect pregnancy a bit earlier than urine tests, sometimes a few days before your expected period, so consider this if you need earlier clarity.

If you’re worried right now

  • If you had unprotected sex in the last 5 days and don’t want to be pregnant , ask a pharmacist, doctor, or clinic about emergency contraception as soon as possible—it’s time-sensitive.
  • If it has already been about two weeks or your period is late , you can take a home pregnancy test today and then repeat in a few days if the result doesn’t match how you feel.
  • If you get positive results or confusing/contradictory ones, a healthcare provider or clinic can confirm with a blood test and advise on next steps.

TL;DR: You can’t tell right away; for most home tests, aim for about 2 weeks after sex or from the first day of a missed period for a reliable answer, and use emergency contraception within 5 days if you’re trying to prevent pregnancy.