Bloody tissue TMI

I've been to the dr for it . they are trying to tell me it's from and infection I'm on antibiotics and he seems to think the treatment will stop it. He did an internal and said he can see bloody mucus discharge and spots that are bleeding on the outside of my cervix.. however it's not just bloody mucus this is what I've been passing for 3 weeks now. Can someone tell me if they have experienced this? I don't think the drs are correct, how could it be from a simple infection!?