Doubt in values. Between two blood test.

Hello Sir/Mam, My husband was suffering from severe fever of about 101 F  which is after a week travel and that too he drove the car all time. We went to our local doctor where we don't have that much good opinion on them and gone for a time being. There they made a blood test and shown result as positive for typhoid fever and started to give medicines.Then, for further doubt has come and reached our trusted doctor.. Then they also made a blood test and shown their result as negative for all other kind of fever including typhoid.he is fine without having medications from both theirprescriptions except anti biotic tablets with self knowledge. Here my doubt is how could the values get differ from hospitals... That too, time gap of one day between two blood test.