Count Ovulation Calendar. Using an ovulation predictor or ovulation calendar can help you determine when you are most likely to ovulate. The fertile days of a woman's menstrual cycle leading up to the ovulation days are the days when a woman is most likely to get pregnant.

Ovulation calculators work by adding the menstrual cycle length to the date the last menstrual period started and then deducting the luteal phase to arrive at a predicted ovulation date. When am i likely to ovulate?