What's my chance of pregnancy?

I don't feel pregnant nor have a scare but have recently became sexually active and want to know my chances of becoming pregnant. I take the combination birth control pill perfectly everyday at the same time sometimes on weekends I'm an hour or so out but my doctor said that's more than ok as I have a 12 window to be protected. My boyfriend uses condoms every time and knows how to correctly put them on and off, and puts them on before any penetration. My boyfriend also pulls out as I am worried about pregnancy as it's really something I'm trying to avoid! What are my chances of becoming pregnant? I'm trying to be as safe and sensible as I can.