Menstrual Cycle Calculator
Free menstrual cycle calculator. Enter the date of your last period and your average cycle length to predict your next periods, ovulation dates, and fertility window.
Between 21 and 35 days
Between 3 and 7 days
What Is the Menstrual Cycle?
The menstrual cycle is the monthly process that prepares the female body for a potential pregnancy. It is counted from the first day of one period to the day before the next. A normal cycle lasts between 21 and 35 days, with an average of 28 days.
Phases of the Menstrual Cycle
Menstruation (days 1-5): Shedding of the uterine lining. Follicular phase (days 1-13): Egg maturation. Ovulation (around day 14): Release of the egg. Luteal phase (days 15-28): Uterus prepares for implantation.
How Is the Fertile Window Calculated?
Ovulation generally occurs 14 days before the next period. The fertile window spans roughly 5 days: 2 days before ovulation, the day of ovulation, and 2 days after. Sperm can survive in the reproductive tract for up to 5 days.
Frequently Asked Questions
Is it normal to have irregular cycles?
Variations of a few days are normal. However, if your cycles are consistently shorter than 21 days or longer than 35 days, it is advisable to consult a gynecologist.
Can I use this calculator as a contraception method?
No. This tool is for informational purposes only. Cycles can vary due to stress, hormonal changes, or other factors. It should not be used as a contraceptive method without medical supervision.
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