Worried. Please read

My boyfriend and I have sex about once a week (sometimes more) and I have been using birth control properly for the past 6 months and we always use a condom every single time. I even have him pull out way before he is close to cumming and I finish him off outside of me. I know there is always a small small chance of getting pregnant no matter what I do but should I worry about getting pregnant??  because I worry about it every time we do it :(