The reproductive cycle
Menstruation usually starts around age 11, but can begin years earlier or later for some women.
- The average monthly cycle is between 28 and 30 days, starting with the menstrual period, which typically lasts three to five days.
- After that, the lining of your uterus (endometrium) thickens, preparing for a possible pregnancy.
- Around day 14, your ovaries will release an egg (ovulation), which moves into the fallopian tube.
- If the egg is not fertilized, the cycle will restart, shedding the egg and the uterine lining (the menstrual period).