Pull out and birth control..

My SO and I have been together for awhile and have always used condoms and I have been on the BC pill for 3 years and haven't missed a pill but sometimes take them a little late. Anyway last night we had sex with out a condom for the first time just to see how it was and it felt a million times better for the both of us!! So we kept going and he pulled out. He didn't come inside me but I'm just wondering what are the chances of pregnancy cause we would like to do it again! Thanks!