If you are not pregnant, other causes of missed or irregular periods include:
- Excessive weight loss or gain. Although low body weight is a common cause of missed or irregular periods, obesity also can cause menstrual problems.
- Eating disorders, such as anorexia or bulimia.
- Increased exercise. Missed periods are common in endurance athletes.
- Extreme emotional stress.
- Travel.
- Medications, such as hormonal birth control methods, which may cause lighter, less frequent, more frequent, or skipped periods.
- Hormonal abnormalities, which cause fluctuating levels of the hormones needed to support menstruation.
- Illegal drug use.
- Problems with the pelvic organs, such as imperforate hymen, polycystic ovary syndrome or Asherman's syndrome.
- Breast-feeding. Many women do not resume regular periods until they have completed breast-feeding.
Premature ovarian failure is when you stop menstruating before age 40. Surgery, chemotherapy, and radiation therapy to the abdomen or pelvis may cause premature ovarian failure.
Other diseases such as irritable bowel syndrome, tuberculosis, liver disease, and diabetes can cause missed or irregular periods, although this is rare. However, if any of these diseases are present, you will usually have other symptoms besides menstrual irregularities.
If you've skipped a period, try to relax. Restoring your life to emotional and physical balance can help. Many women miss periods now and then. Unless you are pregnant, chances are your cycle will return to normal next month.
Hope it helps...