There are different kinds of tests for COVID-19. Molecular tests (also known as PCR tests) detect genetic material from the virus. Antigen tests detect proteins from the virus. Antigen tests are very specific for the virus but are not as sensitive as molecular tests. This means that a positive result is highly accurate, but a negative result does not rule out infection.
If your antigen test result is negative, you should discuss with your healthcare provider whether a molecular test would help with your care, and when you should discontinue home isolation if necessary. If a molecular test is not available, the CDC recommends that you should stay home until three things have happened:
1. You have had no fever for at least 24 hours (one full day of no fever without the use of medicine that reduces fevers).
2. Acuteness of other symptoms has lessened (for example, when your cough or shortness of breath has improved).
3. At least 10 days have passed since your symptoms first appeared.