Your menstrual period starts when hormones trigger your body to start shedding the uterine lining, exposing small blood vessels and causing them to bleed. Menstrual clots usually indicate a heavy flow. People may wish to see a doctor if the blood clots are very large or very frequent.
Verywell / Emily Roberts How Menstrual Clots Form . Passing blood clots during menstruation can be normal. However, when the blood flow outpaces the body’s ability to produce anticoagulants, menstrual clots are released. Period clots are comprised of the endometrial lining that builds up in … However, passing large blood clots …

This blood clot formation is most common during heavy blood flow days.

The blood clots that can emerge from your vagina during your period are a bit different than these other types, though. Cancer: In some cases, blood clots during your period can be a sign of uterine or cervical cancer, but this is very rare.

The amount, length and frequency of menstrual bleeding vary from month to month and from woman to woman. Noticing blood clots in your menstrual blood is perfectly normal.