Have you ever been tested for an immunodeficiency or an autoimmune disorder? Many times, small symptoms like frequent infections are the only symptoms some people get. I would talk to your doctor about making sure your blood work is okay.
Also, some people naturally have a higher temperature that sticks with them. Mine usually runs low in the 97's, (unless ill), but I know friends who are constantly in the 99's.
Try and keep track of your symptoms, in a log or something, even when you feel healthy. This will help you and your doctor note any patterns or changes in symptoms. Take note of any extra stress or relief that may affect you.
I would ask the doctor for testing for autoimmune problems and things like CMV, etc..
If your culture comes back negative for a urinary tract infection and your white blood cells aren't showing an infection, you need to be cautious about taking antibiotics, as your body can build resistance to them.
If you are still having urinary tract infection type symptoms, but the culture comes back negative, you might ask the doctor if he would check you for interstitial cystitis, which can give symptoms mirroring a urinary tract infection.
Stress in itself can make you feel tired, so taking steps toward stress management would be a plus if you are having anxiety due to stress.
See private message for some more info.