also known as On The Rag
Menstruation is a woman's monthly bleeding, also called a period.
When you menstruate, your body is shedding the lining of the uterus
(womb). Menstrual blood flows from the uterus through the small opening
in the cervix, and passes out of the body through the vagina. Most menstrual periods last from three to five days. From Women's Health Dot Gov