The term “great aunt” is generally used to refer to menstruation. Ovulation taking birth control pills menstruation will usually be delayed no more than 1 week, when delayed more than 1 week to rule out the possibility of pregnancy. Ovulation usually take the emergency contraceptive pill, need to be taken under the guidance of a doctor, and exclude contraindications such as liver and kidney insufficiency, to be taken within 72 hours after unprotected sex, may be nausea, vomiting, menstruation delay and other side effects. But generally will not delay more than 1 week, when delayed more than 1 week need to rule out the possibility of pregnancy. Emergency contraceptive pills are only effective for one time of unprotected sex, and you still need to take contraceptive measures when you have sex again, and due to the high hormone dose of emergency contraceptive pills, and many side effects. It is not as effective as the short-acting pill, so it is not recommended as a regular form of contraception. For women who do not want to have children, they can take measures such as placing intrauterine rings, condoms and oral short-acting contraceptives.