You can test for ovulation at any time of the day, but experts suggest the morning, as it may give you the best results. If your typical menstrual cycle is 28 days, you would perform an ovulation test 10 or 14 days after starting your period. "Ovulation occurs 14 days prior to the onset of menstrual bleeding (the period)," says Dr. Gersh. "For [people] with a 28-day cycle, it usually occurs 14 days into the cycle (mid-cycle)." You may even be able to tell when your ovulation is happening by changes to your body. "Some can tell ovulation is occurring by the change of their cervical mucous and an increased sex drive," Dr. Gersh explains.