Birth control

I'm scared that I might be pregnant but I might just be worrying about nothing. I have had light cramps and back ache for a couple days and I start my period in 3 days. I've been on  birth control for 3 months and me and my boyfriend always use condoms too but we didn't a few days ago but he pulled out. I'm still really paranoid about getting pregnant and I take my pill on the same time everyday but I have been a hour late a couple times. Is there any possibility I could be pregnant?