Menstruation mostly occurs in adolescence, and the average age is 12- 18 years old. Very few people have their period earlier than 10 or later than 18. Today's medical field shows that the age of menarche is related to heredity, nutrition, weather and environment. Nutritional status is the main factor that causes the great difference in the average age of menarche among girls. /question/ 125802798.html
Whether you are tall or short depends mainly on genetic factors. If your parents are not short, you will grow taller in the future, which is also related to the day after tomorrow, such as diet and exercise.
Everyone's physique is different, and the time of menstruation is also different. In modern society, people have better living conditions, generally developed earlier, developed breasts, leucorrhea and so on. It means that your body is already developing. When the eggs in the ovary mature, they will come out of the ovary, enter the uterus and finally come out of the uterus. At this time, it is the official holiday. I am 13 years old this year, and my body is already developing. Don't be too anxious, don't be too nervous, try to relax, it's time. . . . . . If you don't understand these aspects, you can communicate with your mother. May you be healthy and happy!