I Have A Very Weird Menstrual Cycle. I Don't Get

I have a very weird menstrual cycle. I don't get one every month, I don't have cramps, and I only bleed for a few days(3-4). For some reason the second week of December I started to experience cramps and a brown discharge. It look like blood on a tampon except it was more of a blood clot type thing. On the 27th I started actually bleeding and its super heavy and then it would stop and I would be so dry I couldn't insert a tampon. After a few minutes I would feel wetness on my thighs and I would be bleeding heavily again. I am still bleeding today two weeks after I started my period. Is this normal? Should I be worried? Should I go see someone about it?