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 I took another home pregnancy test a month later and it also said negative.  But it has been two months already and I haven’t got my period yet. Please help. Is there something wrong with me?

The birth control shot, or Depo-Provera, is a hormonal birth control method used to effectively prevent pregnancy. The hormones prevent ovulation – the process when the ovaries release an egg – and thicken cervical mucus.

With that being said, Depo will be 97-99% effective in preventing pregnancy. The shot is an injection of hormones given every three months; only four times a year! The shot is given by a medical provider into your arm or hip. It will be most effective if taken on time, every time.

One of the most common side effects of the Depo shot can be irregular bleeding, or not having a period at all. How Depo reacts to a person’s body will vary from person to person. Depo has a hormone in it called progesterone. When someone is on a progesterone only method (like the Depo shot), it is not medically necessary for them to have a period. When someone is on a progesterone only method, the lining of their uterus is not building up. When the lining of the uterus is not building up, there is no lining to shed to create a period.

If someone is on a method that has estrogen in it (like the pill, patch, or ring), they need to have a withdrawal bleed or period.

When someone starts a new hormonal method of birth control (like the Depo shot), they need to use a back up method (like condoms or practicing abstinence) for one week before that method will be effective. After that first week, the hormones will be integrated into the body and can help prevent pregnancy up to 99% when taken correctly.

Although you were given a pregnancy test before you started on the Depo shot, it still wouldn’t have been protecting you from pregnancy until after that first week. If you abstained or used a barrier method that first week and have been on time in getting your shot every three months, you will be up to 99% protected from pregnancy.

If you had unprotected sex in that first week of having the shot or have not gotten your next shot on time, pregnancy could be a possibility.

The only way to know for sure if you’re pregnant is to take a pregnancy test 14 days after unprotected sex. After that initial 14 days, you will get an accurate result. If you’ve taken two pregnancy tests at least 14 days after sex, you can trust those results.

Because the Depo shot does not protect against STIs, it’s also a great idea to consider condoms  and dental dams when you’re engaging in sexual activities. If used correctly and consistently, condoms can help prevent pregnancy and STI transmission by up to 98%! Teen Clinic offers free condoms and dental dams.

You can always make an appointment at Teen Clinic to get a pregnancy test, or to talk with a medical professional about your sexual health questions! Call us for more information 303-442-5160.