(NEXSTAR) – You feel a tickle in your throat or a pounding in your head. Or perhaps you’re trying to be cautious before a large family gathering. Maybe a friend you saw yesterday says they’ve tested positive for COVID-19. In any case, you take a COVID-19 test.

If your results are negative, does that mean you’re in the clear? Or is it possible you can test negative and still have the virus?

According to the Centers for Disease Control and Prevention, a negative COVID-19 test result does not necessarily mean you’re free of infection.

Both at-home and lab tests are looking for SARS-CoV-2, the virus that causes COVID-19. When used properly, they’ll show a positive result if SARS-CoV-2 is detected, and a negative result if it’s not. But even if the virus is not detected, it could still be there in small amounts.

If you have symptoms of the virus and still are testing negative, the CDC says, “You may have COVID-19, but tested before the virus was detectable, or you may have another illness, such as the flu.”

If you continue to have symptoms, you may want to test again 24 to 48 hours later, when your viral load may be higher. You may also consider getting a PCR test at a testing site, which is more sensitive and may detect the virus earlier in the infection cycle.

If you do not have symptoms, but you tested because you had a close contact with someone who was sick with the virus, the CDC says a negative result is likely accurate. “You are likely not infected, but an infection cannot be completely ruled out,” the agency advises.

The CDC emphasizes COVID-19 tests are good at detecting whether you currently are infected with the coronavirus. They do not indicate, however, whether you will have the virus and/or be contagious at any point in the future. That means you could test negative one day and test positive the next. That’s why the CDC recommends testing five days after an exposure, and then again one to two days later if you test negative.

You can order eight free at-home tests from the government per household.