When am I most fertile?

In order to get pregnant, a sperm must meet and fertilize an egg, so any factors that affect this also affect your fertility. These include: the timing of ovulation, how long the egg lasts, whether there are any sperm present and how long sperm can live inside you.

Women who have regular periods can easily calculate when ovulation occurs. Ovulation almost always happens 14 days before you expect your period. For a woman who has 28 day cycles, that would be in the exact middle of the cycle, 14 days after the last period and 14 days before the next one. Women who have 30 day cycles can expect to ovulate 16 days after the last period, which is 14 days before the next one.

Women who have irregular cycles cannot predict when they will ovulate. In retrospect, they can calculate that ovulation occurred 14 days before a period, but that does not help in planning a pregnancy. Women with very irregular cycles may need to use ovulation predictor kits to determine when they will ovulate. Ovulation predictor kits detect the rise in hormones that occurs before the egg is released.

It is not necessary to time intercourse to coincide with ovulation. That’s because both the sperm and the egg can live inside you for a while. The egg can last approximately 24 hours after ovulation. If sperm are available anytime during this 24 hour window, you can get pregnant. You don’t have to have sex within the 24 hour window, though. That’s because sperm can live inside you for days, waiting for the egg to be released. You can get pregnant by having intercourse anywhere from several days before ovulation to a day after ovulation.

For example, if you ovulate on day 14 (counting the first day of your period as day 1), you can get pregnant by having sex anytime between days 9-15, and perhaps days 8 and 16 as well. Conception will take place on day 14 or so, but you may have had sex many days before conception.

The bottom line: You don’t have to time sex to coincide with ovulation. If you have sex at anytime within days of ovulation, you can get pregnant.