Hi there... you have hypomenorrhoea ie scanty menstruation.. sometimes it's genetic and normal if you sister , mother had same.. other causes include low
thyroid hormone level, high
prolactin level, high insulin level, high androgen level, Ocp usage, hormonal intrauterine devices, Psychogenic factors such as stress due to exams, or excessive excitement, low body fat, anemia, rarely ashermans syndrome.. please consult gynecologist once for complete examination and treatment..