The word "early" is relative when it comes to your period, according to the website Women to Women. Although a 24- to 29-day cycle is the accepted norm, your body doesn't always follow the textbook. "Early" means early for you. No woman's periods are exactly the same from month to month. Early menstruation should only be considered a problem if it begins happening to you repeatedly. These are called anovulatory periods.
Physical Conditions
Most anovulatory periods have physical causes. Your periods are dependent upon your body's production of estrogen and progesterone. Anything that affects the balance between these two hormones may potentially cause changes in ovulation. If you ovulate early or not at all, or if you produce an egg that is not mature, your cycle will probably be shorter, notes 34-Menopause-Symptoms website. Physical conditions that may repeatedly cause irregular periods, according to Women to Women, include polycystic ovarian syndrome -- caused by an estrogen dominance that affects your progesterone levels -- and chemotherapy treatments for cancer and uterine abnormalities.
Perimenopause
If you are in your late 40s, early periods might indicate a transition into menopause. Your cycles might be shorter some months, or you might skip a period entirely as your progesterone levels begin to fluctuate. If perimenopause is the reason your cycles are shortening, you'll probably notice increased irregularities over a period of four to six years until you stop menstruating completely.
Diet
Substantial weight gain or strenuous dieting may affect your periods. Specifically, diets that are high in carbohydrates may be the culprit. An extremely unbalanced diet, such as those common to eating disorders, may alter the proteins in your brain that are responsible for triggering ovulation, explains Women to Women.
Anxiety and Stress
Anxiety signals your adrenal glands to produce cortisol, a stress-related hormone. Cortisol production affects both progesterone and estrogen levels. Overwork and fatigue on a prolonged basis will cause stress on your body, triggering higher cortisol levels.
Tobacco, Caffeine and Alcohol
Smoking tobacco, caffeine consumption and heavy drinking of alcohol affect ovulation. Your body recognizes dependency on these substances as a source of stress and will increase its output of cortisol. Alcohol also disrupts your liver's ability to metabolize progesterone and estrogen, and this may affect your cycle.
