Excessive bleeding after sex

sarah

So I recently got a Depo shot, and now every time my Bf cums in me I bleed excessively, not like a clotted blood like a period more like fresh blood as if I had a cut but it's a lot. But when we have sex and he finishes outside I'm fine only when he cums inside do I bleed. Any ideas? Is it possible it's not from my depo shot at all, has anyone experienced this before