A woman’s fertile window is the day the egg is released from the ovary and five days beforehand. Sperm can live for up to about five days, but eggs can only be fertilized 24 hours after being released from the ovary. Couples can have sex during the fertile window so that the egg and sperm can meet in the fallopian tube to create an embryo.
1. Menstrual cycle diary
Couples should track the length of the woman’s menstrual cycle to predict the date of ovulation. Cycle lengths vary between people or even from month to month. Couples may need to track multiple months, or even a year of ovulation, to make a better prediction of ovulation. Tracking the cycle on a diary, journal or app can provide a close but not exact starting date.
2. Body temperature
Basal body temperature (BBT) is the temperature of the body at rest. The best time to measure BBT is in the morning as soon as a person wakes up. After ovulation, a woman’s body temperature increases by about 0.5ºF. Ovulation typically happens about four days after the temperature surge.
3. Ovulation hormone testing
Ovulation prediction kits detect an increase in the luteinizing hormone (LH), a hormone that assists the female reproductive system. LH levels increase 24-48 hours before ovulation. An LH surge signals the release of an egg from the ovaries. The best time to use the prediction kits is after the woman notices an increase in cervical mucus.
Increasing the chance of conception
Couples should aim to have sex as close to the day of ovulation as possible. Having sex 6 days before the ovulation day has almost no chance of leading to a pregnancy. While having sex 5 days before ovulation can increase the chances of pregnancy, having sex on the day of ovulation yields the best results. For more information, make an appointment with a fertility specialist or OB/GYN.