Maternal and Child Care: Because menses is the only external marker of the cycle, however, the first day of menstrual flow is used to mark the?

Question

Because menses is the only external marker of the cycle, however, the first day of menstrual flow is used to mark the?

James Marion Endrina Entice · Accepted Answer

beginning day of a new menstrual cycle.

Because menses is the only external marker of the cycle, however, the first day of menstrual flow is used to mark the?