Several factors can cause early periods, or mid-cycle bleeding, including excessive weight loss, ovarian cysts and pelvic inflammatory disease, according to Mayo Clinic. Irregular cycles can also indicate non-cancerous g... More »

Irregular periods are generally not cause for alarm, but in some instances may signify an underlying medical problem, according to EverydayHealth. As many as 30 percent of women during childbearing years have irregular p... More »

It is possible to experience both normal and unusual vaginal bleeding while on birth control, WebMD states. This may include early periods, shorter periods, reduced flow, and spotting in between periods. More »

Causes of irregular periods include emotional stress, breastfeeding, excessive weight loss or gain, and eating disorders such as bulimia or anorexia, states WebMD. In rare cases, conditions such as liver disease, diabete... More »

Causes for a two-week long period include uterine fibroids or polyps, endometriosis or pelvic inflammatory disease, according to EmpowHER. In women over the age of 45, long periods can indicate the beginning of menopause... More »

Stress and extreme weight fluctuations may cause the menstrual period to arrive a week early, according to CNN. For some women, antidepressants, thyroid disease or polycystic ovary disease is the culprit. More »

There are many reasons why a woman’s period might come early, including severe weight loss or gain, certain medications, metabolic syndromes, endocrine disorders, stress or the onset of perimenopause. Experts consulted b... More »