Post Partum Sex 20 weeks? Bleeding?

So, the boyfriend and I are officially back into the swing of things and everything is going great. Except, I bleed every time we have sex, sometimes it's light bleeding and other times (2 days ago) I bleed like I was on the 3rd day of my menstrual cycle but I only bled for about 10 minutes. It was so embarrassing, he swore that he "scratched me on the inside" with his nails or something lol. I'm like idk I can't imagine bleeding that much from a scratch. I had small bits of stuff coming out too (sorry for the graphics) but I have know wth is going on.