I got my first Depo injection 5 days before my period was due. I took a pregnancy test at the clinic before I was given the injection and it was negative. I did not get my period after the injection…

… and had unprotected sex 14 days later. He did not ejaculate inside me and pulled out. A month later I got my period. Am I safe from pregnancy? Is it normal to bleed?

Thanks for getting in touch—it’s responsible to learn how your birth control method works!

Many people do not get a period at all while on Depo. Other people experience irregular spotting or bleeding.  That’s because Depo contains high levels of progesterone, a hormone that makes it hard for the lining to form on the uterus.  Remember, a period is just the blood-filled lining of the uterus shedding each month. (For a refresher on the menstrual cycle, read this question.) If there’s no lining, there’s nothing to shed—so a person taking high levels of progesterone may not get her period.  In other cases, a person may develop a small lining, but it may be unstable, shedding a little bit at a time instead of at the end of the month. This can look like abnormal bleeding.

If you had any unprotected vaginal intercourse before you were given the Depo injection, there may still be a small chance of pregnancy. Take a pregnancy test to be sure! However, if you waited at least 7 days after your first Depo shot to have unprotected sex, it’s likely you were protected from pregnancy. If taken on time, Depo is 99.7% effective in preventing pregnancy—but don’t forget that Depo never prevents STIs!

It’s healthy to realize that no hormonal birth control is 100% effective.  Even the most effective methods on the market—like IUDs and Implanon—prevent pregnancy only 99.9% of the time.  In very rare cases, someone becomes pregnant even though they are using a method correctly. Teen Clinic recommends using condoms 100% of the time as a backup, and to prevent STI transmission.

If you have more questions, consider visiting Teen Clinic to talk to a practitioner. Our nurses are non-judgmental and here to support you! And thanks for asking this important question!