Talk to Gynecologist on Menstrual Cycle

Hello doctor, I wanted to discuss my menstrual cycle. For the last 1–2 months, I’ve been getting my period twice in one month. The first period is normal, but the second time I have very little bleeding — mostly dark or brown blood that looks old. It comes from the uterus but not like a regular period. I’m not having much pain, but I’m worried about why this is happening. Please guide me if it could be hormonal or something else