Hi, I Am A 40 Year Old Male With No

Hi, I am a 40 year old male with no lifestyle releated disease. I have been suffering from fever ranging between 99-99.8F fever which is there only in the evening since 23 March. I have tested negative for covid 19 (3 tests done), negative for malaria and typhoid. My blood report and urine test report are normal. Chest X ray is clear. There is no cough or cold.