Bleeding period but what...

Ok so I had my period this month from aug 3rd to the 7th after the 7th I started to bleed again it was on and off then I noticed I was also bleeding from the back of me too so about two weeks later I went to the hospital and they gave me and exam in both front and back she said she thinks it's coming from my hormones.. which to me why am I bleeding for 3 weeks!! And it's a lot too like a heavy period.. from my hormones really? Something don't sound right. I also went to my gyno he did an ultrasound and said everything looked good he just wishes I would go back on birth control to control my hormones but I don't wanna go back on them.. I just wish I knew why I am bleeding for 3 weeks and I know it's still not going away. 😒😔