Remember, it can take 3 to 7 days after infection for there to be enough antigens to be detected by the test. If a person with COVID-19 tests too soon after they become infected, the test result can incorrectly show as negative; this is called a false negative.
Rapid antigen tests are less sensitive than PCR tests. This means that the chances of a false-negative test are higher with rapid antigen tests than PCR tests. The sensitivity of rapid antigen tests is higher for people with symptoms than for people without symptoms.
For this reason, public health recommends using rapid antigen tests only for people with COVID-19 symptoms. People who are eligible for treatment can test with a rapid antigen test as soon as they feel unwell. Seek medical care if you feel you need it, regardless of whether you test positive or negative.
If you are blind or partially sighted and need assistance to read your rapid antigen test result the Canadian National Institute for the Blind, CNIB recommends the free service provided by
Be My Eyes.
For people who are not eligible for treatment
- If your result is negative, it means COVID-19 was not detected. It is still possible that you have COVID-19.
- Stay home until your symptoms improve, you don’t have a fever, and you feel well enough to return to regular activities.
- If you continue to feel sick or your symptoms worsen, repeat the test in 24 hours.
- You may repeat the test every day for 5 days as long as you feel you are not improving. If the test remains negative by day 5 of your illness, it is unlikely you have COVID-19.
- If you are concerned about your health, you should contact your health care provider. They may suggest additional testing based on a clinical evaluation.
If your result is positive, it means COVID-19 was detected. You likely have COVID-19 and you could pass it on to others.
If you are fully vaccinated or under 18 years of age: Self-isolate for at least 5 days from the first day you had symptoms.
If you are not fully vaccinated and 18 years of age or older: Self-isolate for at least 10 days from the first day you had symptoms.
For information on next steps including checking if you may benefit from treatment, ending isolation, managing symptoms, go to:
I have COVID-19
There are some treatments available for people who tested positive for COVID-19, who are not in hospital, and are at higher risk of serious illness from COVID-19. To find out if you may benefit from treatment and how to get the treatment, visit:
- If your test is not valid, discard all the pieces from the first test.
- Wash your hands and repeat the process using a second set of test pieces.
- Follow the test instructions again.