It is normal for girls to experience irregular menstruation when they have their first period. This is because the first menstruation usually occurs between the ages of 11 and 13, which is the puberty period. The ovarian function is not particularly stable and the hormone level is also in an unstable stage, so this can lead to irregular periods. It usually takes 1-2 years before a more regular menstruation occurs. So there is usually no need to be too nervous about irregular periods at this stage. However, if there is an unusually heavy period, it is still necessary to seek medical attention. Because a small number of girls are prone to puberty during menarche, puberty is treated with medication. In addition, it is important to pay attention to the hygiene of the perineum to prevent infection during menstruation, and to learn basic physiological knowledge.