Low Grade fever everyday for 45 Days.

I got reinfected with covid on 24th April. My only symptoms were low grade fever fever and body-ache. I have had CT thorax twice which were completely fine. But the problem still persists. I have every possible blood tests which all come normal. My temperature is 98 in morning and it starts rising through the day, reaches 99.6-99.7 in afternoon and then start declining in evening,comes back normal in night. This happens everyday, even if I take any anti pyretic or not. This comes along with dull headache and limbs ache. . Should I go for PET CT. I'm scared whether it's something related to cancer ? My blood culture report is negative ( normal ) ESR 04, CRP under 1 typhoid and TB negative. RA factor is normal. CBC is normal too. Only CPK is low.