It is normal for girls to have their periods at the age of 10, as long as they are older than 9. The vast majority of women have their periods between the ages of 13 and 15, but due to individual differences, some will have their periods earlier and some will have them later. Girls living in the south will get their periods relatively early, while girls living in the colder areas of the north will get their periods later. In addition, girls in urban areas will have their periods earlier, while girls in rural areas will have their periods later. It is normal to have menstruation if you are not younger than 9 years old or older than 18 years old. It is recommended to take good care of your menstruation and change your sanitary napkin regularly.