For women who take birth control pills and then have intercourse with pregnant women the next day, as long as the child can grow and develop normally, usually can be, because women can successfully get pregnant after taking birth control pills, most of the emergency contraceptive pills, and emergency contraceptive pills can only have a contraceptive effect on the pre-pill intercourse, but on the post-pill intercourse will not have a contraceptive effect, and so it may lead to pregnancy. Emergency contraceptive pills have an all-or-nothing effect on the embryo. Since the embryo is able to grow and develop normally, it means that the emergency contraceptive pills have no effect on the embryo, and that is why the pregnancy can continue. If a woman becomes pregnant and experiences repeated vaginal bleeding, it means that the emergency contraceptive pill has affected the normal growth and development of the embryo, and spontaneous abortion often occurs, which is usually not recommended to preserve the pregnancy but to let nature take its course.