I think this testing is all a joke. I had to get a pre-op test done on a Wed. Thurs I was taken to hosp, by ambulance. They, also, had done a Covid test on me. Who can tell me how the test on Wed came back positive for me having Covid, yet the test done on Thurs came back negative for me having Covid. This makes absolutely NO sense to me. Within less than a 24 hr time span - first I have it then 'poof' now I don't. Hmmm....