90.4 - 102.6

Her fever has been bouncing back and forth from 90.4 up to 102.6 What is up with this.. We have been to the doctor once and she had puss on her tonsills so they immediately swabed her throat but it was negative.. said it's probably a virus and to come back Wednesday if she is still running fever and not better.. we'll be going back.. she just lays around sleeping, and hasn't eaten since Friday. She did take a bite of something Saturday and a bite of something last night and that was it. We are doing Motrin every six hrs. on the dot and it only brings it down a little and for a short time. Is there something going around I don't know about? If anyone knows let me know please.