Interactive Tool: When Are You Most Fertile?

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 are planning a pregnancy, do not have sex during the 5 days before your 6-day fertile window. (Not ejaculating for a few days helps build up a man's sperm count.) Then have sex once each day of your fertile window, including ovulation day.