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.
Pregnancy tests work by detecting a hormone called the human chorionic gonadotropin hormone (HCG). HCG doesn't start being released until the fertilized egg implants itself and pregnancy begins.
If you do not want to be pregnant and you've had unprotected vaginal intercourse, don't wait to take a pregnancy test. Emergency contraception can be started within 120 hours (five days) after intercourse.
Plan B emergency contraception is now available over the counter for women 18 and older. Plan B and other forms of emergency contraception are also available by prescription for all women. Contact your local Planned Parenthood at 1-800-230-PLAN to get EC or to get a prescription for EC if you are younger than 18. You may also get EC at your local pharmacy if you are older than 18.
