If you are 17 years old and have not had your period for several months, if you are not sexually active and pregnancy is ruled out, you are suffering from irregular periods during puberty. The cause of irregular menstruation during puberty is related to many factors. On the one hand, it is related to the unstable level of sex hormones in the body, and on the other hand, it is also related to the fact that the ovarian function is not fully perfected. During adolescence, emotions may be in a relatively volatile state, and it may also be related to irregular diet, stressful life, and environmental changes, all of which can lead to irregular menstruation. If you have not had your period for more than 3 months, you may consider going to the hospital for an ultrasound examination and a comprehensive analysis of the six female sex hormone indicators to take symptomatic treatment. Generally, you can take artificial cycle for menstrual regulation treatment, you can consider the combination of progesterone for menstrual regulation treatment for 3 months; you can also consider taking compound short-acting contraceptive pills for menstrual regulation treatment, which can help improve. You should pay more attention to rest, avoid straining and staying up late, reduce stress, relax, strengthen physical exercise, eat regularly and comprehensively, and avoid partial and picky eating, which can help improve the situation.