Hi,i'm 21 years old and always been underweight. in total,irregularily, i had my period only 12 times since puberty hit me when i was 15 yo, unable to visit a doctor,m asking for any info that can help me understand/solve this situation, thank you?

Delayed or infrequent menstruation is quite common in young, underweight women. Unfortunately, it is not possible to advise on the causes or treatment in any particular case on a distant forum like this. This could be serious; try to see a doctor if at all possible. If your life situation makes it impossible, investigate HealthTap's concierge option, or other telemedicine evaluation. Good luck.

Underweight women have subnormal levels of estrogen and may not be ovulating monthly. Your solution is to gain weight so that you are at a healthy level for your height. As weight and fat percentage increase, more estrogen is released which helps promote normal ovulation and menstrual cycles.