Appropriately Timed Intercourse

When it comes to fertility, timing can be everything.

Most people know that a woman is able to conceive for a short time each month. The question is: when and for how long?

Let's do the math.

Fertility experts generally recommend that you should have sexual intercourse at least every other day just before and after you ovulate. During ovulation, the egg that has matured in your ovary is released and settles into one of your fallopian tubes. After ovulation, this egg will survive for only about 24 hours. A man's sperm, however, can live for 48 — 72 hours in a woman's reproductive tract.

Assuming that a woman has a 28–day cycle and that ovulation occurs around the 14th day of her cycle that means that her most fertile times occur during days 11 to 17 of her cycle. But before you apply this math, take into consideration that not all women have 28–day cycles. The key to timing your intercourse is knowing the length of your cycle so you can estimate when ovulation occurs. It's also important to understand that this "fertile window" can be highly unpredictable, even if a woman's menstrual cycle is usually regular.[1]

Predicting ovulation.

Pinpointing the precise day when ovulation should occur is a bit of a challenge. The easiest, but least precise, way to predict this is to chart your menstrual cycle on a calendar. Remember, a woman's cycle begins on the first day of her period and typically lasts about 28 days. The first day begins not when a woman is spotting, but when she experiences regular flow.

Once it is known how many days a woman's cycle generally is, subtract 14 days from the predicted end of the cycle to determine time of ovulation.

Another option may be to use a basal body temperature (BBT) chart. To measure BBT, a woman simply takes her temperature every morning when she wakes up and charts it on a calendar. Her BBT should rise about a half degree two days after a surge in her luteinizing hormone (LH) occurs, indicating that ovulation has happened. Physical release of the ovum (egg) probably occurs on the day prior to the first temperature elevation.

You can also buy an ovulation predictor kit at your local drug store. They're available without a prescription, are simple to use, and can usually predict ovulation 24 to 36 hours in advance. The kit works by measuring increases in a woman's LH level just prior to ovulation.

Unfortunately, these methods are not perfect. For more information, talk to your healthcare provider.

Natural Monthly Cycle

View the day–by–day animation of a woman's natural monthly cycle