Women sometimes don't ovulate every month for a number of reasons. If you have menstrual cycles that occur every 23 to 35 days and you have symptoms of breast tenderness, bloating, pelvic or uterine cramping, or mood changes 3-14 days prior to your menstrual cycle, you probably are ovulating. However, if your cycles are usually over 35 days, you may not be ovulating consistently or not at all. The majority of women who do not ovulate and are not pregnant, may have Polycystic Ovary Syndrome (PCOS). PCOS is a condition that you are born with and can cause a woman not to ovulate (release an egg) on a regular and consistent basis. These women may also have adult acne or an increase in hair growth above the lip or below the chin. On ultrasound, the ovaries may be seen to have many small cysts inside them, that remain at a small size. Other conditions that can cause you not to ovulate include low thyroid function (hypothyroidism), high prolactin production (hyperprolactinemia), and during the time period prior to the menopause (perimenopause). If you feel that you are not ovulating consistently, you should see your health care provider.