Women can get from time to time ovarian
cysts. Usually they are simple
cysts and not dangerous. I have had one myself.
And they pass on their own. While you have them, you can have irregular bleeding, pain, hormonal changes. Then when they pass, it is painful. You often also have heavy bleeding. It is like a super magnified bad period with cramps and bleeding. Then you pretty much go back to normal after. I had one 15 years ago and do not think I've had any others since.