Unusual spongy dark brown discharge during menstrual cycle

I am on my 4th day of my menstrual cycle (it last 5 days) This time my period was lighter than normal but I know my cycles change. However, this time I had an unusual discharge. I had an urge to use the restroom because I thought I needed to poop; I was unable to, I just peed. When I wiped, I saw this dark brown,seahorse shape (I know it sounds ridiculous but that was the shape), spongy discharge on the toilet paper. ( I touched it and the texture made me whoozy)