calculate menstrual cycle for months
Ovulation calculator. Our ovulation calculator will tell you when youâre most likely to be fertile over the next six months. To increase your chances of getting pregnant, just tell us the first day of your last period and how long your cycle usually lasts (between 20 and 45 days).vulation calculator. Our ovulation calculator will tell you when youâre most likely to be fertile over the next six months. To increase your chances of getting pregnant, just tell us the first day of your last period and how long your cycle usually lasts (between 20 and 45 days).