What Causes Spiking Fever With Headache And Stomach Ache?

Hello there, I have a question in reagrds to fever. My daughter was sent home from school Tuesday morning. she was not feeling well (headache and tunny ache) she came home and slept for 5 hrs. she then began to show signs of a fever. Wednesday we went to the doctors and got a precription for possible strep/mono. she has taken the precription once a day for 2 days now. I havent seen any improvment. My only concern is the fact she shows no other sign or symptoms of strep or mono - the only thing she has is a fever, and it will spike to 103.5 at some times. now it does come down with advil, but not on its own. Is there anything I could do ? could it be something else ? (not mono/strep)