The main reason for breast pain after taking birth control pills is that birth control pills are a combination of estrogen and progestin, and the mammary glands will only change under the effect of estrogen and progestin, so people who are relatively sensitive after taking birth control pills will experience bilateral breast swelling and pain, which is a side effect of birth control pills. It is recommended to take better local care of your breasts, and most of them will return to normal after you stop taking the pill. In the case of contraceptive pills in daily life should be noted: 1, do not use the pill in the case of breast enlargement, because it may aggravate the local symptoms. 2, the case of uterine fibroids also can not use the pill contraception, you can use other methods of contraception.