Postpartum sex

So my baby is six weeks old today and I've been to the doctor for my check up and told everything is okay so my husband and I decided to have sex. I'm getting birth control pills but not on them yet and we're gonna do the pull out method but we've never pulled out before. So, today when we had sex he totally forgot about pulling out so he came in me. Has anyone else done this and did you get pregnant or not? Next time we'll definitely be using more protection, today we were just in the moment and it's been so long neither of us could wait any longer. So, anyone have any advice? Also, I breastfeed and supplement with like 2 bottles a day of formula.