Precum

I just started bc, I'm into my second month. I got a UTI and was taking macrobid for it (my doctor said it wouldn't affect my bc) anyways me and my bf had sex without a condom for about a week and he pulled out each time before cumming. BUT we went at it a couple times in a row and he didn't pee in between to "clear out the sperm" which is what I heard he was supposed to do. So I'm worried that there was sperm in his precum the next few times we went at it and I'm worried I'm at a risk for pregnancy. I know that I'm on the pill but still...