Bleeding halfway through cycle , don’t know why

Sa

I’m currently on CD 15 and should be in my fertile window, except yesterday I had super light spotting and today it looks like a whole new period? I don’t have any history of PCOS or endromitosis so I don’t know what else could be causing this heavy blood flow midway through my cycle. Does any one know what this could be? Should I be going to a hospital or something? This has never happened. I also had a stillbirth on June 13th if that changes anything.