Chances of pregnancy?

Hey guys, i get a little paranoid here and there but I’ve been on birth control for 2 and a half months now for the first time taking the pills. I use cryselle -28, and I’m 17. I take my pill at 10 Pm every night and I’ve never missed a pill or threw it up. I’ve had diarrhea before but only during the day, not around the time i take my pill. So basically I’m great with taking my pills on time every night.

I have sex every week like 3 times with no condom on. My bf would cum in me just a little bit when we do it but not often tho. He came in me like 4 times within those 2 and a half months of me taking the pill.

What are my chances of getting period, my birth Control failing? I know i shouldn’t worry because i am protected but isn’t it minimal?