What does it mean if I test negative?
A single negative test result does not mean you are free from infection. It simply means that you did not have COVID-19 at the time of testing, or the sample was collected too soon after you were infected.
False negatives are more likely than false positives, especially in the first days after exposure. The test is most accurate three to seven days after exposure. If you suspect your test result is inaccurate, you should get tested again.
If you suspect that you’ve been exposed, the safest way to protect those around you is to self-quarantine. Here’s more information from the CDC.