The onset of menstruation generally occurs in 12-13 years of age. The first menstrual bleeding at ages 9-16 is normal. You can expect your menstruation to start between 2 and 3 years after your breasts started to develop. If menstruation begins before the of age 8 or does not begin after 16, medical examination may be required.
Of course, you need to know that the onset of puberty varies from person to person. In this case the most important factor is inheritance. This means that the time when get your first period is closely related to your mother’s or sisters’ menarche. In addition, factors such as nutrition, weight, and general health are also effective in your menstruation onset. Also the influence of climatic conditions on age at menarche is important. This means that if you live in tropics, you may have an earlier onset of menarche than those who live in cold areas.
Your period, as the name suggest, follows a timeframe and usually happens once a month. However, there may be a gap of several months or even a year between your first and second menstrual periods, which is fine. It can take up to two years for your menstrual cycle menarche to become regular.