I would look research the IC diet and see if diet changes help your symptoms - removing caffeine, sodas, high-acid foods, etc., can make a difference. It is common to have symptoms flare around your cycle with IC. With luck, you've caught it fairly early, and some simple treatments can reduce and even eliminate your symptoms. :-)
Are you having a cystoscopy with hydrodistention?If they don't fill your bladder with the distilled water they will not see the pin ***** bleeding or inflamation that they need to diagnose IC. I really hope you dr gives you a lot of local cause mine said that it would be torture for anyone to have it done locally.He only does them under general.I would also reccomend a pelvic specialist.I hope you find some relief soon.Not sure if you know of this product or not but its called Pre-lief.You can order it from your drug store.You take it before you eat and it takes all the acid out of the food that would irritate your bladder lining.
I'm right there with you with the exact same bladder symtoms- except I've already had the cystoscopy with my urogynocologist. That test didn't show any abnormalities so she sent me to a Pelvic Pain Specialist, as I also have ovarian cysts, which may or may not be pressing on my bladder causing the symptoms. I am scheduled to have my ovaries out on October 12th- at the same time, he will do a cystoscopy with distention to see if I have IC, which he strongly suspects. If you can, I would strongly suggest finding a Pelvic Pain specialist in your area- I was at my wits end, but now hopefully, I'll soon have answers.
Good luck to you- there IS light at the end of the tunnel :)