broken condoms....

my fiancé had a fabulous night at a jazz club so naturally I was feeling a little frisky....I'm on one of my last period days and had only spotted very lightly today. at the end of our intimacy, we realized in about 60 seconds, the condom broke. I can't help but laugh because I feel like it can't be real but literally less than a minute previous to the climax it was fully intact. my question is, what is the likely hood that I could conceive from this broken situation? I am my THAT worried about it but I am curious :)