An ovarian cyst is a fluid-filled sac in the ovary.
Many cysts are completely normal.
These are called functional cysts. Functional cysts normally shrink over time, usually in about 1 to 3 months. If you have a functional cyst, your doctor may want to check you again in 1 to 3 months to make sure the cyst has gotten smaller. Or your doctor may want you to take birth control pills so you won't ovulate. If you don't ovulate, you won't form cysts.