Some reasons for a period being 5 days early include stress, severe weight loss or weight gain or perimenopause, according to the National Institutes of Health. It is normal for women to have irregular periods. Significant changes, however, should be brought to a doctor's attention for diagnosis.Continue Reading
If a woman has regular periods, every 28 days like clockwork, it can be worrisome if her period is a few days early one month. Women's hormones can be thrown out of whack with any number of things, resulting in her period being a few days early or late. According to the NIH, in addition to the usual stress, weight changes or perimenopause, there are other reasons for an early period.