What could possibly be causing a constant discomfort in my urthrea after my doctor and I have done three urine analysis with all three coming back negative for everything including blood and white blood cells? There is also no discharge and no burning when I pee. All STDs have been tested except herpes and all are negative. I am planning on taking a herpes test. Any idea what else can cause a constant discomfort in the my urethra gland area?