How do I know if I have irregular periods?

Your menstrual cycle is considered irregular if it varies more than a few days in length from monthto month. It's normal to have an irregular cycle or two now and then. But if you continue to haveirregular periods, or if you don't have a period at all for three to six months, it's time to see yourdoctor.

Most menstrual cycle intervals occur about every four weeks, with the normal range between 21 and35 days. To calculate your menstrual cycle, start counting from the first day of your last period andstop counting on the first day of your next period.

Many factors can affect your cycle, including hormonal shifts, changes in your diet or exerciseroutine, stress, and weight gain or loss. But a few unusual periods in a row could signal a problemsuch as polycystic ovary syndrome or uterine fibroids.

An irregular period may also be related to endometrial hyperplasia, a condition where the lining ofthe uterus becomes too thick. However, this is usually only a problem when hormones change as awoman hits menopause.

If you see only a very small amount of blood around the time you expect your period, you could bespotting as opposed to actually menstruating. Spotting can happen when you ovulate, duringpregnancy, after sex, or as a symptom of a medical problem. Hormonal birth control methods canalso cause spotting.

If you're spotting between periods, let your doctor know.