Im facing the problem of not having periods.my gap between first and 2nd cycle may vary from 2-3 months.im experiencing this problem by the age of 15?

Ovary or adrenal: Hi. Do you have any male hair growth (hirsutism)? Irregular periods and hirsutism (& usually overweight) could be polycystic ovaries. Irregular periods could also be a manifestation of several adrenal disorders including non-classical congenital adrenal hyperplasia or Cushing's syndrome. See your doctor for a good history & exam & appropriate testing. Good luck.