Taking birth control pills generally cannot be detected, no matter which kind of contraceptive pill, and there is no effective way to detect the concentration of birth control pills in the blood. Oral contraceptives can be categorized into short-acting, long-acting and emergency contraceptives, and most of them are composed of estrogen or progesterone, which will lead to an increase in estrogen and progesterone in the body after a woman takes them, but there is estrogen and progesterone secretion in the body of every woman, so there is no way to check it at present. It should be noted that if you want to use contraceptive pills for contraception, it is not recommended to take oral emergency contraceptive pills, because emergency contraceptive pills have a large content of hormones, long-term use of which has a certain effect on the body.