The menstruation (also known by the names of period) is the bleeding that women have when the egg is not fertilized, which was expelled from the ovary to be fertilized. It occurs as part of the menstrual cycle of women, and we can consider it as a normal vaginal bleeding. This bleeding can be excessive and abundant (what is medically known as menorrhagia) or be totally and absolutely normal.
Menstruation is part of the menstrual cycle, which begins on the first day of menstruation and tends to last around 28 days, although a cycle may actually last for between 23 to 35 days, be completely regular, however stays ahead or delayed.