Periods aren’t typically a surprise-until they show up a day or two early while you’re wearing white jeans.
While, yeah, it’s unsettling to see anything other than bright red on your tampon or pad, it might be more common than you think. If periods are good at anything-besides, you know, clearing your body of built up uterine lining-it’s keeping you on your toes.
Black period blood is just “blood that’s older, that’s started to clot a little bit,” says Rachel Peragallo Urrutia, M.D., an assistant professor of general obstetrics and gynecology at the University of North Carolina.
When the lining of your uterus starts sloughing off once a month, the blood doesn’t always come out right away and the longer the blood sits in the uterus, the darker it gets, says Urrutia.
Uturria says nothing can really change the color of period blood-though if you’re concerned with the amount of bleeding that comes with your period, you can talk to your doctor about birth control options like an IUD that might help reduce bleeding a bit (or get rid of your periods altogether).
Still, it’s important to always pay attention to your body and the signs it’s giving you. If you’re concerned about your black or dark blood, bring it up during your next ob-gyn appointment-while it might not point to anything scary, it’s worth having peace of mind.