You should not test immediately after a COVID exposure; most people are advised to wait about 5 full days after the last close contact before doing a first at‑home antigen test if they have no symptoms. If you develop symptoms at any point, you should test right away and repeat testing if the first test is negative.

When to test after exposure

  • If you have no symptoms :
    • Wait at least 5 full days after your last close contact, then take a test.
* If that test is negative, repeat testing every 48 hours for a total of 3 tests over 5 days (for example: day 5, day 7, day 9).
  • If you do have symptoms (sore throat, congestion, cough, fever, body aches, etc.):
    • Test as soon as symptoms start, even if it has been fewer than 5 days since exposure.
* If the first antigen test is negative but you still feel sick, repeat the test after 48 hours or get a lab (NAAT/PCR) test, because early infection can be missed.

Why not test too early?

  • After exposure, the virus usually needs a few days to reach levels that a test can detect, so testing in the first couple of days is more likely to miss an infection.
  • That is why both public‑health and testing authorities recommend waiting at least 5 days if you are asymptomatic , and using serial tests (multiple tests over several days) to be more confident in a negative result.

What to do while you wait

  • Wear a well‑fitting mask around others for 10 days after your last exposure, especially around people at higher risk (older adults, those with chronic conditions, pregnant people, immunocompromised).
  • Watch for any new symptoms and avoid close contact with high‑risk individuals until you finish your testing window and at least 10 days have passed.

If your test is positive

  • Stay home and away from others and follow the latest local or national guidance on how long to isolate and when it is safer to be around people again.
  • People at higher risk for severe COVID (older age, certain medical conditions, pregnancy, weakened immune system) should contact a healthcare professional quickly, as treatments like antivirals work best within the first few days of symptoms.

Information gathered from public forums or data available on the internet and portrayed here.