An ovarian cyst is produced by the ovaries. This is a part of ovulation. Ovulation occurs during a woman's menstrual cycle. The menstrual cycle happens every month in a woman's body. The length of time it takes for ovarian cysts to grow is about a month. These cysts can grow inside or outside of the ovaries. They are usually harmless, but can sometimes cause a problem. If there is an issue with an ovarian cyst, it will be removed and analyzed.