Inflamed bladder

I went to the doctor and was told that my bladder seems to be inflamed because white blood cells showed up in my urine. 
Idk why but I am so scared right now while waiting for my results to come back to what's causing it. 
Has anyone had that before? 
Internet says it could be caused by a UTI but I've had a UTI before and it does not feel like I have one now.