My Core body temp is low in the 96 area for years.?

When I go to the drs with something like bronchitis or pneumonia they'll take my temp and it's 97.5 for instance, they'll tell me that I don't have a temp. I keep telling drs that my core temp is lower than normal and they tell me that doesn't matter. I've seen it reach 99.9 ... It just makes sense to me that if my core temp is lower than normal, why isn't 1 or 2 degrees higher a slight fever? Why are drs insisting that I don't have a temp? I feel hot.