soooo because of the fact my highschool gives NO education on sex i think i am overthinking this situation but i wanted to check first...

i want to start off by saying i have been on birth control for about 2 and a half years now and have probably only delayed taking the pill twice but it hasn’t been recent. a couple days ago i had sex for the first time with a condom, it wasn’t ripped but it did actually fall off at one point and my boyfriend was careful to take it out of me in a safe way. i have a little bit of anxiety though that that there is a chance the condom slipping off could possibly get me pregnant. Also to add to my anxiety I started what I thought was my period yesterday and then today I am no longer bleeding, I start the last week of my birth control pills tonight though so it could also be some spotting before my period?