I bet a lot of the testing has been contact tracing with known infected and people coming back from infected areas. Going to get a lot of negatives that way. I seriously doubt it's because hypochondriacs are showing up with a runny nose at the dr's office and getting tested as some would have you believe.
As well as health professionals that have displayed symptoms, but probably didn't have COVID-19. A good friend of mine's wife had a fever and cough that came and went in about 3-4 days. She's the admin of a nursing home, and they obviously weren't going to let her return to work without a negative test, so she was able to get tested and came back negative.