Aunt's early. What's going on?

Normal said aunt is menstruation, normal menstrual cycle is 28 days plus or minus seven, that is, 21 to 35 days. The so-called menstrual cycle is shorter than 21 days, more common reasons may be endocrine disorders caused by food, such as spicy, too tonic, as well as mental factors such as depression, as well as environmental changes, such as from one place to another, water and soil are different, due to drugs caused by menstrual advance more common in contraceptives. If the menstrual flow is small and early, you must also pay attention to excluding the possibility of pregnancy. For different reasons to be dealt with accordingly.