Here's how to take a rapid COVID-19 test accurately at home

SAN FRANCISCO -- The recent outbreak of the omicron variant has many people running for the store for an over-the-counter rapid test. But simply taking the test once isn't enough to tell you if you have contracted COVID-19.

So you think you've been exposed to COVID-19? You run to the store and pick up a rapid test. It comes up negative. You're in the clear...right?

RELATED: Exposed to COVID at a gathering? What to know about quarantining, testing

Well, maybe.

You see, those over-the-counter antigen tests are capturing whether COVID-19 is present at that "exact" moment you take the test. It doesn't tell you if you have COVID-19.

You may still be positive, but you will need to wait to be sure.

That's right, wait.

RELATED: What to know about rapid COVID at-home tests

The demand for COVID-19 testing has surged as President Biden is making 500 million free rapid tests available to Americans next month.

According to the Centers for Disease Control and Prevention, those over-the-counter rapid tests were approved by the Food and Drug Administration to be used twice over a three-day period, with at least 24 hours, and no more than 48 hours between tests.

If that second test comes back negative, you can assume you are in the clear and do not have COVID-19.

If the test results indicate you are positive, you have COVID-19.

The CDC recommends that you take yet another test five days later.

RELATED: What the new CDC quarantine guidelines mean for you

Doctors explain the CDC's shortened COVID isolation guidelines.

Yep. More waiting.

If that test comes back negative, you can end your isolation but will still want to wear a mask, because you may still be contagious.

If that test comes back positive, you are likely still contagious and can spread the virus to other people. You'll need to continue to isolate, taking another test every day until the results are negative.

The most reliable tests continue to be those PCR tests. They are highly effective at identifying the virus, but the tests only detect the presence of the virus, they won't tell you if you are likely to infect other people. That's because some people will test positive for weeks or even months after they were infected with COVID-19, and may not be spreading the virus.