You can usually take a pregnancy test about 2 weeks after unprotected sex , but the most reliable time is after your missed period (often around 3 weeks after sex, depending on your cycle). Testing too early can give a false negative because the pregnancy hormone hCG may not be high enough to detect yet.

Quick Scoop

  • Most home urine tests are accurate from the first day of a missed period , which is roughly 14 days after ovulation and often about 2–3 weeks after unprotected sex.
  • Some “early detection” tests may show a positive a few days before a missed period, but they are less reliable and more likely to miss an early pregnancy.
  • If your periods are irregular, many experts suggest waiting 2–3 weeks after unprotected sex for a more trustworthy result.
  • A blood test at a clinic can detect pregnancy a few days earlier than most urine tests but still generally needs about 10–14 days after sex to be meaningful.
  • If you do not want to be pregnant , emergency contraception can usually be taken up to 3–5 days after unprotected sex , and it works best the sooner you take it.

How Pregnancy Tests Work

  • Home tests check your urine for hCG (human chorionic gonadotropin) , a hormone made after a fertilized egg implants in the uterus.
  • Implantation usually happens about 6–12 days after fertilization , and hCG becomes detectable in urine a couple of days after that.
  • That timing is why many sources say the earliest realistic window is around 10–14 days after sex , with accuracy improving every day after your missed period.

Practical Testing Timeline

  • Too early (0–6 days after sex): No test will be accurate yet; fertilization and implantation may not have even happened.
  • Early window (7–10 days after sex): A few very sensitive tests might pick something up, but false negatives are common.
  • Better window (~14 days after sex): Many home tests start to be reasonably accurate around this time.
  • Best window (after missed period): Highest accuracy for home urine tests, especially if you follow instructions exactly and use first-morning urine.

If Your Test Is Negative But You’re Worried

  • If you test before or right when your period is due and it is negative, but your period still does not come, retest in 3–7 days.
  • If you keep getting negative tests, but you have pregnancy symptoms or very delayed periods, it is wise to see a healthcare provider for evaluation (and possibly a blood test).

Safety Note

If you had unprotected sex recently and are concerned about pregnancy, STI risk, or need emergency contraception options, consider talking to a doctor, nurse, or clinic as soon as possible; they can give time‑sensitive advice tailored to your situation.