Ovulation 101

KEY POINTS

  • Ovulation is when your ovaries release an egg. It happens about 14 days before the first day of your period.

  • You can get pregnant if you have unprotected sex any time from 5 days before you ovulate and the day of ovulation.

  • Use the March of Dimes Ovulation Calendar to figure out when you ovulate.

  • Some birth control methods may affect ovulation and how soon you become pregnant. 

What is ovulation?

Each month your ovaries release an egg about 14 days before the first day of your period. This is called ovulation.

You can get pregnant if you have unprotected sex any time from 5 days before and the day of ovulation. Your egg is fertile (can become an embryo) for 12 to 24 hours after ovulation. Your partner’s sperm can live inside you for up to 72 hours after you have sex.

How do you know when you ovulate?

Here are some ways to help you figure out when you're ovulating:

  • March of Dimes Ovulation Calendar. Use our tool to help you figure out when you ovulate.
  • Basal body temperature. This is your temperature when your body’s at rest. Use a basal body thermometer to take your temperature every day before you get out of bed.  A basal thermometer measures small changes in your temperature. For most women, your temperature rises slightly (0.5 to 1°F) when you ovulate. The 2 to 3 days before your temperature rises are the best days to try to get pregnant. Taking your basal body temperature can tell you when ovulation has already happened, but if you track it over a few months, you may be able to predict when you’ll ovulate in the future.
  • Cervical mucus. Pay attention to the mucus in your vagina. It increases and gets thinner, clearer and slippery just before ovulation. For the best chances of getting pregnant, have unprotected sex on the days when your mucus is the most thin, slippery and clear. Another way to check cervical mucus is to check it twice every day. If it increases for 2 days in a row, it’s a good time to have unprotected sex to try to get pregnant.
  • Ovulation prediction kit. Use this kit to test your urine for a substance called luteinizing hormone (also called LH). This hormone increases each month during ovulation and causes the ovaries to release eggs. You know you’re ovulating when your LH increases.

If you’ve stopped using birth control, how long should you wait before trying to get pregnant?

There’s no right or wrong amount of time to wait, but the kind of birth control you used may affect how soon you start ovulating. For example:

  • If you were using birth control pills, you may begin ovulating about 2 weeks after you stop taking them. But your periods may not be regular for a month or 2 after.
  • If you were taking Depo-Provera, it can take 10 months or more after your last shot before you ovulate regularly. Depo-Provera is a birth control shot that you get every 3 months.
  • If you had an implant or an intrauterine device (also called an IUD), you can start trying to get pregnant as soon as you have it removed.
  • If you were using a barrier method of birth control, you can start trying to get pregnant as soon as you stop using it. A barrier method keeps a man’s sperm from reaching a woman’s egg. Barrier methods include male and female condoms.