Menstrual Blood Girls, Learn more. Jul 27, 2025 · The menstrual phase is your actual period, or when you’re shedding your uterine lining and bleeding. Menstrual fluid is the correct term for the flow, although many people prefer to refer to it as "menstrual blood". Menstruation — aka having your period — is when blood and tissue from your uterus comes out of your vagina. As the uterus sheds its lining, vaginal bleeding follows. . It usually lasts 3 to 5 days, and often overlaps with the follicular phase. Your menstrual cycle begins on the first day of your period. Menstruation is the most visible phase of the menstrual cycle and its beginning is used as the marker between cycles. Throughout the month, your hormone levels change depending on what menstrual phase you’re in. o3, 622jr, v5, de, r1aa5, ijo, kghnm, rrytc, 9zkv0, t29e,