Ovulation is the release of a single, mature egg from a follicle that developed in the ovary. It usually occurs regularly, around day 14 of a 28-day menstrual cycle. This is the most fertile period of your cycle. Ovulation is the ideal period of your cycle when your chances of getting pregnant are highest. Your fertile period starts about 4-5 days before ovulation, and ends about 24-48 hours after it. This is because sperm can live in your body for approximately 4 to 5 days, and the egg can live for 24 to 48 hours after being released. In normally fertile couples there is a 25 percent chance of getting pregnant each cycle, meaning around 75 to 85 percent of women who have sex without using birth control will get pregnant within one year. You can boost your chances of getting pregnant by learning exactly when you ovulate by understanding the cyclic hormonal and physical changes that take place in your body each month.