Is missing a period normal?

Periods are often irregular during the first few years after menstruation starts. It may take several years for the hormones that control menstruation to reach a balance. Many teens have irregular menstrual cycles because their body is getting used to releasing hormones. Some reasons for an irregular period 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. For more information, see the topic Anorexia Nervosa or Bulimia Nervosa. 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.

Disorders of the thyroid gland can cause menstrual irregularities if the levels of thyroid hormone in the blood become too low or too high. Some women have irregular periods because their bodies produce too much androgen, which is a hormone that causes increased muscle mass, facial hair, and deepening of the voice in males and the development of pubic hair and increased height in girls.

Because you are only 18 this is definitely normal. If your irregular period becomes a menace you can always go on birth control which helps to regulate your menstrual cycle. If you choose not to, just always try to be prepared.