I have the exact same issue. I seems to be the body slowing fighting back. My fever doesn't go over 99.8 and I don't take tylenol or anything to break it. I feel like it is my body fighting. I am on IVs so I will start a lactate ringing if it is persistance and that seems to help level out the temp. I can feel when it is spiking, so hook up a latcate ringing and stretch back in the recliner.
I hope it makes you fell better that it is normal.