Health Tools

Health Tools help you make wise health decisions or take action to improve your health.

	Interactive tools are designed to help people determine health risks, ideal weight, target heart rate, and more.
	Peak Fertility

What do the results tell me?

Your "fertile window" is up to 6 days long, once a month. It includes:

• The day you ovulate. This is when you have the best chance of becoming pregnant. (A human egg usually lives for only 12 to 24 hours after ovulation. This is why you are not likely to get pregnant by having sex a day after you ovulate.)
• The 5 days before ovulation. This is because sperm can live in a woman's body for 3 to 5 days after sex. When an egg is released, one of these sperm is ready to fertilize it.

If you want to become pregnant, try to have sex every day or every other day from your first fertile day to your last fertile day.

What's next?

If your periods are irregular, this calculator is not a good way to predict your ovulation dates. Do not use this tool to prevent pregnancy.

For more information, see the topics Fertility Awareness, Pregnancy, and Fertility Problems. If you are looking for information on birth control, see the topic Birth Control.

Source: Speroff L, Fritz MA (2005). Clinical Gynecologic Endocrinology and Infertility, 7th ed. Philadelphia: Lippincott Williams and Wilkins.