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 early after they become infected, the test result can 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 for people with COVID-19 symptoms only. 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.
- If your result is negative, it means COVID-19 was not detected. It is still possible that you have COVID-19.
- Self-isolate until your symptoms improve and you feel well enough to return to regular activities.
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, and are not in the hospital, and who 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 the second set of test pieces.
- Follow the test instructions again.
- If you have two invalid test results, get a COVID-19 test at a testing location. Find a testing location.