If you miss your menstrual cycle what are other things that can be wrong?

Need more info: If you are a person whose menstrual cycle is very regular and suddenly it has stopped, we need to think about causes. Oral/IM contraceptives, pregnancy, stress, nutritional deficiencies, weight loss, excessive exercise, eating disorders, excessive weight gain and mental health medications can all cause irregular periods. If any of these fit your situation, small modifications may help. See a DR