Taking birth control pills before checking out a pregnancy may have an effect on the fetus. The effects of taking birth control pills on the baby are classified as all or nothing. If there is abdominal pain and vaginal bleeding precursor to miscarriage in early pregnancy, birth control is not recommended, indicating that the baby may not be healthy. If intrauterine pregnancy is diagnosed and growth is good, you can continue the pregnancy and do the pregnancy checkup program. Checking for pregnancy only after taking birth control pills may have an effect on the fetus, thus you need to strictly follow the requirements of the maternity checkups, if there is any abnormality in order to detect the problem in time. Any abnormality during pregnancy, you need to go to the hospital as soon as possible, the doctor according to the specific circumstances, to develop individualized treatment plan, so as to avoid delaying the time of treatment.