How soon after sex can pregnancy be detected?
Pregnancy tests can detect pregnancy after a missed period — some can even detect it before a missed period.
Despite what some people think, pregnancy doesn’t start the day a couple has intercourse. It can take up to seven days after sex for the sperm and egg to join and form a fertilized egg. Then, it can take up to eight days, or more, for the fertilized egg to bury itself in the lining of the uterus. Pregnancy begins when this happens.
If you do not want to be pregnant and you’ve had unprotected vaginal intercourse, don’t wait to find out two weeks later with a pregnancy test. Emergency contraception can be started within 120 hours (five days) after intercourse. Emergency contraception is available without a prescription from pharmacies, under the name NorLevo or PlanB.