A period usually lasts between 3 to 5 days during which you lose blood mixed with shed uterine tissue. The color of menstrual blood will change through the period, and you may wonder what colors are normal. Periods usually begin with heavy bleeding, and for the first few days, it is normal to see bright red blood. If your flow is especially heavy, it is not unusual to experience dark red blood with clots, and it should not alarm you.
As the period progresses, the flow gets lighter and blood starts to change from bright red to rusty brown. This happens because the blood reacts with air and oxidizes to change color, so brown discharge at the end of your period is totally normal. Some women who experience very light periods may not have bright red bleeding at all, instead, their periods may be pinkish-red.
Period blood varies widely in color and quantity, but if your periods become unusually light or heavy, it is always a good idea to consult your doctor!