Is the cyst causing you pain? Is she doing anything to try to shrink it during those six months or is she just trying to watch to see if it grows?
I would definitely seek a second opinion if it is causing you pain and/or she is just watching for growth.
If it's causing you pain, you may be able to go to the ER and get emergency surgery. I had a dermoid cyst about the size of a softball in my right ovary back in '09, and I had no knowledge of it until that day when they did the CT scan. Went into the ER thinking I had appendicitis but had a cyst removed instead.
Hi there and welcome. Ugh, sorry you are going through this. Well, you are under doctor care which is a good thing. If you are not trusting your doctor, then I'd seek a second opinion. That's about all you can do. I've had a cyst and also had a slightly irregular period. I will tell you that it also was a very heavy period and many cramps when it passed. Nothing unbearable but wanted to let you know that. These types of cysts are not uncommon.
If you feel that your questions aren't answered or your health is in jeopardy, I would certainly seek a second opinion. Lots of luck to you