The question you have asked is a very important one, but its answer is dependent on a couple of factors which you haven’t included. First, it is dependent on your age. Since you are continuing to have periods, I am assuming that these are “natural” periods and that you are not menopausal. If this is true, then having a small cyst on the ovary is not uncommon. In fact, you make a cyst each month as your follicle develops and you ovulate. If the cyst is classified as a simple cyst, meaning that it is fluid filled and doesn’t have any solid tissue included in it, no other treatment or follow-up is needed. If you were menopausal, the treatment would also be based on the size and type of the cyst. If the cyst is simple (no solid component) and less than 4.0 to 5.0 cm in size, the likelihood that the cyst is a cancer is extremely unusual. In some cases it might be helpful to obtain a CA-125 blood test. If this test is in normal range, the cyst is simple and small, and there is probably no reason to seek any additional treatment. You also asked whether you should talk with your gynecologist. Absolutely, you should always feel free to talk with your physician about any concern that you have.