My scan says polycystic ovaries but my periods are regular. Do I really have PCOS?

Having polycystic-looking ovaries on a scan is not the same as having PCOS. Many women, especially in their twenties, have ovaries with lots of small follicles but ovulate normally and have no other features of the syndrome. PCOS is usually diagnosed using the Rotterdam criteria, which need at least two of three features: irregular or absent ovulation, signs of high androgens (on blood tests or as acne, excess hair or scalp hair thinning), and polycystic ovaries on ultrasound, after ruling out other causes such as thyroid problems or high prolactin. With regular cycles and no signs of excess androgens, the scan finding alone doesn't meet these criteria. In adolescents, ultrasound isn't used for diagnosis at all because the appearance is so common. Regular 28 to 30 day cycles suggest you're likely ovulating. If you want reassurance, a doctor can confirm ovulation with a mid-cycle follicle scan or a progesterone test about a week before your expected period, and may check androgens. If you're under 35, try for up to a year before seeing a specialist, or six months if 35 or older. See a doctor sooner if your cycles become irregular, longer than about 35 days, or you develop new acne or hair growth.