Chances of being pregnant?

My bf and I stopped using condoms 2weeks ago. I have been on the pill for almost 2 years and I take it everyday (sometime late but I never miss it). We always pull out too for extra protection.

The past couple of days I have felt crampy like I am going to get my period which is weird because the birth control stopped my period. The last one was in June.

The only way I could have gotten pregnant was from precum. Am I just worrying myself? What are the chances I could be pregnant?