How are the days of the menstrual cycle counted?
A menstrual cycle starts with the first day of monthly bleeding. The last day of the menstrual cycle is the day before the next monthly bleeding starts. For example, if bleeding started on July 1, that is the first day of the menstrual cycle. If the menstrual cycle that month is 28 days long, the next monthly bleeding would start on July 29. If this woman usually has 28-day cycles, she can expect monthly bleeding to start again on August 26. How long does the menstrual cycle usually last? Most women have menstrual cycles that last between 24 and 35 days. The most common length is 28 days. But many women have longer or shorter cycles. The length of some women’s cycles varies by a few days from month to month. All these patterns are normal.
