What's wrong? Urinating every 20 minutes, no infection, not kidney stones, not pregnant.?

Help! I have had frequency of urination for a couple of months - had a course of antibiotics but there was no infection and that did not help. I am really bloated and have a lot of pressure, some pain in abdomen. In the past week, the frequency of urination increased to around every 20 minutes during the day and about 5 times during the night. My doctor gave me FloMax saying it might help with the frequency and could help with passing a kidney stone. (At that point, we both thought it was a kidney stone because I have a history of them). Yes, I know Flo-Max is for men. But it is being increasingly used off label for women for frequency and to help pass kidney stones.

He sent me to get a non-contrast CT scan and it showed no kidney stones. It did show a cyst on my left ovary. The nurse told me if the cyst was large enough, it could be causing the frequency of urination. But when I went to the OB/GYN they said it wasn't large enough (only 2.6cm).

The OB/GYN is trying to send me to the urologist without sending me back to my GP (not sure if my insurance will accept that). And I would like to check out non-invasive tests before they stick the scope up there, ok? What I'm wondering is: has anyone else had symptoms like these and what did it turn out to be? I see similar questions on here but no one ever seems to come back and say what it was after they find out.

This is driving me crazy. Usually I can figure out what is wrong (or at least narrow it down to a couple of things) so that when I see the doctor, I can make sure he checks those out. I have found this to be important since I have been misdiagnosed in the past (more than once). One time I had the same symptoms as above, the doctor treated me for a UTI even though urinalysis was negative, said if that didn't work, come back and we would try something else. I came back but the doctor did the same - more antibiotics for negative urinalysis. I came back again (by this time I was urinating every 15 minutes and my boss was so mad I thought he was going to fire me) and the dr wanted to do antibiotics a 3rd time in spite of yet another negative urinalysis. But by that time, I had done some research and was pretty sure I had a kidney stone. So I requested she order an IVP x-ray (yes, it's old technology now) and she got mad and said well it isn't necessary and your insurance won't cover it. I told her I didn't care, that I would pay for it myself. Amazingly she did order the test. When she got the results, I received a personal phone call from her saying she was sorry, that I DID have a kidney stone and it was obstructing my left ureter and I needed surgery immediately. I appreciate that she had the guts to apologize personally. So, anyway, that (and a couple of other incidents I will spare you) is why I like to have some IDEAS of what to ask about when I go into the doctors office.

Anyone else's experience and results? Please!!