pull out method

I usually have taken birth control but this month I was unable to go to my appointment due to class. so I haven't taken it and my boyfriend and I also pull out on top of that. well like I said this month I haven't had it. and yesterday he came inside me on accident. I mean we both loved it but now I'm thinking okay well what if I get pregnant now it's only been about a week since my period. and I've read articles about how sperms can live inside for like five days. so less than five days from now I'm ovulating. we aren't trying for a baby. but I mean we've been together for eight years. it wouldn't be the end of the world. what are my odds? anyone have any experience with this? I would love to hear it