Have you been checked for yeast infections or just high levels of yeast? I know that when I have yeast infections I can have similar symptoms as a bladder infection. Also, you can have an "over active" bladder that contracts too much and causes a bad burning sensation without having any infection. (I have had periods of constant bladder infections and this other over active thing throughout the years). This is a treatable condition with a type of muscle relaxer. You may want to ask your doctor about it. One more thought...are you using a lubricant or spermacide? Some people are hightly sensitive to these things.