Based on your menstrual cycle, when's the best time to have sex so you have the lowest chance of pregnancy? – Maura* The time a girl is most likely to get pregnant is about halfway between periods, when ovulation happens. Ovulation is when an egg is released from the ovaries. But trying to time things to a "safe" time can lead to an accidental pregnancy. That's because it's very hard to predict exactly when the egg will be released. And girls can be fertile for several days before and after they ovulate. Couples having sex should use a more reliable birth control method to prevent pregnancy, like birth control pills or the patch. And always use condoms to help prevent STDs. *Names have been changed to protect user privacy. Back to Articles Related Articles Birth Control Methods: How Well Do They Work? Some birth control methods work better than others. This chart compares how well different birth control methods work. Read More STDs (Sexually Transmitted Diseases) You've probably heard lots of discouraging news about sexually transmitted diseases. The good news is that STDs can be prevented. Find out how to protect yourself. Read More Emergency Contraception Emergency contraception is a way to prevent pregnancy after unprotected sex; for example, if a condom breaks or slips off during sex. It is also available to teens who are forced to have unprotected sex. Read More Fertility Awareness Learn what the fertility awareness (rhythm method) of birth control is and how it works - and some of the reasons why it might not work for teens. Read More Do You Need a Pelvic Exam to Get Birth Control? Find out what the experts have to say. Read More Talking to Your Partner About Condoms Some people - even those who are having sex - are embarrassed by the topic of condoms. Here are some tips for talking about condoms with your partner. Read More About Birth Control Before you consider having sex, you need to know how to protect yourself. Read this article to get the basics on birth control. Read More Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2021 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.