Bladder infection

So I received a phone call from my OB, she said I tested positive for a bladder infection. I've had the hospital tell me that too in the past, then they went back to check and said they were wrong. I have no symptoms of an infection. Has this happened to you? And if I do in fact have one, besides the prescription I have to take now, what is best thing to have eating or drinking to get rid of it?