A menstrual cycle begins with the first day of menstruation, and ends with the day prior to the day of the next menstruation.
It includes menstrual, follicular, ovulation, and luteal phases.
The menstrual phase involves shedding of the inner lining of the uterus in preparation for the new cycle.
During the follicular phase a new ovum, a female reproductive cell, grows to its maturity. Its growth culminates in ovulation-maturation of the ovum, followed by its descent from the ovaries into the uterus, where it can become fertilized by a sperm cell. This is the period of fertility.
After ovulation the luteal phase takes on. This is the phase, when the walls of the uterus are lined up with new layers of cells, which are necessary in case ova become impregnated with sperm. If pregnancy did not take place, the uterine lining sheds, which is associated with the next menstrual cycle.
Menstrual cycle and the energy of Moon
Synchronicity with the Moon cycles lies at the heart of Classical Chinese gynecological model.
Ideally, a menstrual cycle has a duration of a lunar month, which is approximately 29 days.
In this model the menstrual phase comes at the time of the full moon. This time is called the monthly tide.