Why am I bleeding???

Alright! So I started my period on the 21st of August and it ended on the 26th...the only thing unusual about it was that it was really really heavy. It's normally heavy, but I was having to change out my super plus tampons after an hour of having them in. My period ended on the 26th, and now I've had brown discharge since Saturday which is also pretty normal because I'm ovulating but I'm also cramping pretty bad and then today I started bleeding again...why am I bleeding again??? It wasn't pink either it was really bright red. Has this ever happened to anyone else? I'm kinda worried.