How long should I wait after getting the shot to have sex?
If you get the birth control shot (also known as Depo-Provera) within the first seven days after the start of your period, you’re protected from pregnancy immediately. Otherwise, you need to use some form of backup birth control — like a condom, female condom,diaphragm, or sponge — whenever you have intercourse during the first week after getting the shot.
Each shot will protect you from pregnancy for 12 weeks. So you will need to go to your health care provider every 12 weeks for a shot. If you are two or more weeks late getting your shot, your health care provider may ask you to take a pregnancy test, or may advise you to use emergency contraception if you had vaginal intercourse in the previous 120 hours (five days).
Learn more about the shot.