When did girls start using sanitary napkins? When can I use it? How many bags do junior high school and high school universities need every day? Do I need to change when I go to the bathroom? Women still need ... Generally, I 10 years old menstruate, and then I menstruate once a month. It's normal for a few days, and it's gone in a week or so! It's best to prepare more bags when you go to school, and 3 sanitary napkins a day is enough! Women also need pads (used in small quantities), sanitary napkins for daily use and night use, and avoid eating cold and spicy food!