Ob-gyns break it down.
— but there may be nothing less predictable than the color of your flow from one day to the next. Period blood ranges from pink to dark red to black, and if you don't understand what causes these changes, they can be unsettling. Fortunately, a range of period colors is not only normal, but expected.
"The color of period blood is really determined by how long the blood has remained in your uterus and vagina," , MD, FACOG, a board-certified ob-gyn and minimally invasive reproductive surgeon, tells POPSUGAR."It gets darker due to the oxidization of blood — the longer it stays around before it is discharged."
The duration, flow, and even the color of a period is extremely individual, but California-based ob-gyn, MD, MPH, FACOG, explains that periods will often start out pink on the first day, then turn bright red for a few days, followed by dark red on the heaviest day, and finally, brown or black for the remaining day or two. POPSUGAR asked the experts what each of these different period colors mean, so you know exactly what to expect.