Help:)

This post is mostly to calm my anxiety. A month ago I switched to a different brand of birth control pills with only 4 period day pills and 24 active pills. I always take them on time. When I started the new pills I had unprotected sex multiple times through that month and at the end of the month I got my period for about 4-5 days. Then I had unprotected sex multiple times again after. I’m just a little worried I might be pregnant. All the times I’ve had unprotected sex, he pulled out. I take the pill at the same time. I guess I am just worried because I have been having cramps and lower back pain. I just want to ease my mind.