COVID-19 At-Home Rapid Test Frequently Asked Questions

This test detects proteins from the virus. If it is positive, it means you likely have been infected with the virus and can be contagious to other people. The other type of COVID test is a PCR test, which detects molecules of RNA from the virus. It detects more cases of COVID, but it takes longer to come back and is processed in a professional lab.

The following is general advice about how to interpret your antigen test results. Please talk to your medical provider if you have any questions about your particular situation.

COVID symptoms include runny nose, sore throat, body pain, headache, feeling tired, fever, cough, loss of sense of smell or taste, and shortness of breath. If you have these symptoms and you test positive, it is likely you have COVID. You do NOT need another test such as a PCR test to confirm the positive result. Isolate for 5 days from the start of your symptoms.

It is still likely that you have been infected with COVID. If your test is positive, with or without symptoms, you should isolate for 5 days. You can consider getting a PCR test to confirm, but you should still self-isolate until your results come back. Often, it will be about 5 days before you can schedule a PCR test and get the results back, so we recommend isolating for at least 5 days if this antigen test is positive.

You need to self-isolate for at least 5 days from the start of your symptoms.

  • Day 0: First day of symptoms or positive test if NO symptoms.
  • Day 1–5: At home and away from other people in your home.
  • Day 6: OK to end home isolation if no symptoms or improving, and no fever for 24 hours. You still need to wear a mask around others until end of isolation. You STILL may be contagious at this this point.
  • Day 10: Last day of isolation and wearing a mask around people, if symptoms are resolving.

If you are Codman Square Health Center patient, please reach out to us at 617-825-9660 or seek emergency care. If you do not go to Codman Square Health Center, please reach out to your PCP’s office, or seek emergency care.

It is likely the test is wrong (often called a “false negative”). You can either confirm the result with another rapid antigen test, take a PCR test, or just isolate for 5 days from the start of symptoms. If you decide to confirm with a PCR test, you should isolate until the results come back.

It is likely the test is correct that you are not infected with COVID. Occasionally, “false negative” results do occur, and you could confirm with a PCR test or another antigen test. You do not need to isolate because you do not have symptoms. If you are testing because you have been exposed, please follow the quarantine guidance at