To determine when ovulation occurs, if your cycles are regular, subtract 14 days from the length of your cycle, according to Parents.com. Ovulation typically occurs on day 14 in a 28-day cycle. For irregular cycles, you can determine the occurrence of ovulation by tracking your temperature, using an ovulation prediction kit, or watching for changes in your cervical mucus.
To track temperature, take your temperature each day at the same time before getting out of bed, recommends Parents.com. Approximately 24 to 48 hours after ovulation, a woman's basal body temperature increases about half of a degree. After charting your temperature for a few months, you can detect a pattern to help determine when ovulation occurs. A basal body temperature thermometer is helpful for tracking temperature, as it is more sensitive than a regular thermometer.
An ovulation prediction kit measures the level of luteinizing hormone in urine, explains Parents.com. The kit is available for purchase at drugstores. By urinating on a tester stick, you can determine if hormone levels are rising, which is an indicator that ovulation is about to occur.
As a woman's body readies for ovulation, it produces a greater amount of cervical mucus, notes Parents.com. On the days a woman is most fertile, the mucus is clear, stretchy and slippery, similar to raw egg whites. When ovulation is over, the mucus becomes thicker and later dries up. By collecting daily samples through wiping the opening of the vagina with toilet paper or a clean finger, a woman can monitor changes in her cervical mucus to help determine her most fertile days.