The typical length of time between the first day of one period and the first day of the next is 21 to 45 days in young women and 21 to 35 days in adults (an average of 28 days).
Menstruation stops occurring after menopause which usually occurs between 45 and 55 years of age.
Bleeding usually lasts around 2 to 7 days.
The most fertile day is in the middle of the menstrual cycle or the 14th day.
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