Why do your boobs get bigger when you take birth control? It’s kinda freaking me out cus I know your boobs get bigger when you get pregnant. My placebo pills start this Saturday and I’m anxious. I am hardly ever late taking my pill (latest has been by an hour and a half and that was over a month ago). And my boyfriend always wears a condom and pulls out before finishing. I usually try and check the condom when we are finished but sometimes I don’t. Do you think it’s just my birth control?