If menstruation is delayed for 7 days and pregnancy is ruled out, it is likely to be caused by the following reasons.1. Delayed menstruation due to oral contraceptives, such as taking short-acting contraceptives or emergency contraceptives in clinical practice, may be delayed.2. Delayed menstruation due to endocrine disorders. Due to environmental changes, emotional changes or due to excessive work pressure, can also lead to delayed menstruation. 3, due to delayed menstruation caused by diet, such as dietary inattention, often eat cold food, drink cold drinks, drink frozen drinks may lead to delayed menstruation, so it is recommended that clinically can be taken to promote menstruation medicine. The most commonly used menstrual stimulant is progesterone, which can be taken orally before going to bed once a day, two capsules at a time, for three consecutive days, and will come to menstruation in 3-7 days after stopping the medicine.