Ovarian cysts are common and usually go away on their own. They can cause symptoms of pain or discomfort and can also affect the menstrual cycle since they alter hormones.
Some women always have cysts on their ovaries. There's something called Polycystic Ovary Syndrome (PCOS) where the ovaries contain cysts in a "strand of pearls" pattern. PCOS is a condition of insulin resistance and is associated with a few common symptoms such as excess body hair, tendency to gain weight easily, oily or acne-prone skin, excessive testosterone levels. Of course, you may not have this but thought I'd mention it.