What do you think??

So my bf and I had been together for almost 4 years and we've been using the pull out method. Surprisingly he's good at it and I haven't gotten pregnant yet. I don't take any form of birth control. But yesterday we we're so drunk so we decided to not pull out (once). It was the first time he came inside me. He decided he wanted to build a family with me. Could I get pregnant that one time?? I'm on cycle day 10 and I usually have 35 days cycle. Thanks girls!