Even if you haven’t had your first period, you can get pregnant if you have sex. This is because of something called ovulation, which happens even before you start having periods.

What’s Ovulation?

Ovulation starts in puberty. It happens each month when the ovaries release an egg (the female sex cell). This egg then travels to the lining of the uterus. If you have sex, sperm (the male sex cell) can “meet” or fertilize the egg, which becomes a fetus. If the egg isn’t fertilized, the uterus lining breaks down and bleeds. This is a period.

Each time you have a period, it’s proof that you ovulated in the past 2 weeks and didn’t get pregnant.

How Can I Avoid Getting Pregnant?

If you decide to have sex, use a reliable form of birth control, like an intrauterine device (IUD) or birth control pills, to protect against pregnancy.

And you also need to know about sexually transmitted diseases (STDs). STDs can spread through vaginal, anal, or oral sex; using fingers; or other sexual contact. Using a condom, finger condom, or dental dam each time you have sex can help prevent STDs.

What Else Should I Know?

Your doctor can answer questions about when you'll get your first period. Let them know if you don't get it by age 15 or 3 years after you started puberty. Your doc also can answer questions about sex birth control, and STDs. Or you can reach out to health clinics like Planned Parenthood.