Why is my period dark red brown and very lumpy its also not as heavy usual?

Possible causes of dark red or brown and lumpy menstrual blood:

Old blood: Dark red or brown menstrual blood is often old blood that has been sitting in the uterus for a while before being shed. Old blood can also be a sign of a slow menstrual flow.

Blood clots: Lumps in menstrual blood are often caused by blood clots. Blood clots can form when the uterine lining sheds in large pieces. Clots are more common in women with heavy menstrual bleeding, but they can also occur in women with normal or light bleeding.

Endometriosis: Endometriosis is a condition in which endometrial tissue grows outside the uterus. Endometriosis can cause heavy, painful periods, as well as dark red or brown menstrual blood.

Adenomyosis: Adenomyosis is a condition in which endometrial tissue grows into the muscle of the uterus. Adenomyosis can also cause heavy, painful periods, as well as dark red or brown menstrual blood.

Fibroids: Fibroids are noncancerous growths of the uterus. Fibroids can cause heavy, painful periods, as well as dark red or brown menstrual blood.

Polyps: Polyps are small, noncancerous growths on the lining of the uterus. Polyps can cause heavy, painful periods, as well as dark red or brown menstrual blood.

Cancer: In rare cases, dark red or brown menstrual blood can be a sign of cancer of the uterus or cervix. However, this is not a common cause of dark red or brown menstrual blood.

If you are concerned about the color or consistency of your menstrual blood, it is important to see your doctor to rule out any underlying medical conditions. Your doctor can also help you determine the best course of treatment for your menstrual symptoms.