What does it mean if I test negative for COVID-19 one day and positive the next?
Houston Chronicle, January 6, 2022
It means you have COVID, said Dr. Megan Berman, an associate professor of internal medicine at The University of Texas Medical Branch. False negatives can occur for a variety of reasons, such as being tested too soon after exposure. The virus may simply not be detectable yet in the body, or the sample may not be sufficient, she said.