Chances of pregnancy postpartum?

I'm 4.5 weeks pp. My bf and I were planning on waiting the full 6 weeks before having sex but it kinda happened, and my stupid ass forgot to use condoms since we never have before (we've only been together a year). We had sex this morning and last night but he didn't finish last night. I'm still bleeding a little bit from after birth and haven't gotten my period yet, so what are the odds I could get pregnant?