Stupidity thy name is alcohol

So guess who drank with the boyfriend the night before last? Me. I didn't have as much as he did but I had a bit of coconut rum. So after we go to bed one thing leads to another and we're going at it and it's phenomenal in every way. Usually we'll start sans condom but quickly transition to one well I got lost in the fun and I thought he was less drunk than he ended up being and we went longer than normal and ended up using the pullout method. I still wasn't worried because my period is in less than a week (now 5 days, was 6 days away based on the app).

I asked him if he thought we could do that again only for him to confess he really didn't remember most of it (yay, right?). I don't know if I should go spend $50 on plan b at this point... I don't think I am even pregnant.

What is the likelihood that I even could be?

What should I do? We're both adults in our 30's. (Btw, I feel compelled to mention that the bf doesn't drink's a rare thing)

Regardless I will be looking into birth control to take/use. I prefer the Nuvaring and hate iuds...what about you all??