You do need to see an Infectious Disease Dr. I have had that happen to me many times. Mostly in early evening my fever would start to go up. Would feel good all day and then up it would go up at night. I do have lung disease and come to find out it would be a bacteria in my lungs that would trigger all of this. I have learned when this happens , start my spectrum samples to the dr. They usually find a bacteria. Listen to your body. A fever is not normal when you are not sick. Hope that you can find the right Dr to figure this out. Isn't it always the way . . . you go to the Dr and they say everything is fine and you go home and get sick that night! It is truly a mystery and they call it practicing medicine for a reason.