How to Determine When a Woman is Fertile. A woman's fertile period is the time when sexual intercourse is most likely to result in conception. If you are trying to get pregnant-or avoid getting pregnant-use the following tips to determine when a woman is most fertile.
Estimate the date of ovulation, or the release of the egg. Women generally ovulate mid-cycle which, for the average woman with a 28-day cycle, is about 14 days after the first day of her period. A woman's fertile period begins four to five days prior to ovulation and lasts one to two days afterward. This is because the egg lives for one to two days after it is released, and sperm can live in the woman's body for up to a week.
Use an ovulation predictor kit to not only determine when, but if ovulation will occur. The kits are fairly simple to use, generally requiring the woman to urinate on a test strip that detects a surge of lutenizing hormone (LH), the hormone that triggers ovulation. Ovulation generally occurs within two to three days of a rise in LH so intercourse during this time period has a higher chance of resulting in conception.
Chart basal body temperature. Women who take and record their temperature every morning at exactly the same time before rising from bed can chart their basal body temperature. Temperatures peak a couple of degrees during ovulation, so intercourse just prior to this surge is more likely to result in conception.
Examine cervical mucous for changes. This discharge tends to be slippery and stretchy in texture (think of egg whites) three to five days prior to ovulation to allow sperm to more easily reach the egg. It also tends to be more alkaline in composition to allow sperm to live longer in the woman's body.
Once a woman's fertile period has been determined, have intercourse every 48 hours to increase chances of conception. The two-day waiting period between attempts allows the man's sperm levels to build back up to an optimum volume.