This can be a challenging question and there is significant information and clinical decisions to be made, based upon that information to make the best recommendations about testing.
If you previously had a confirmed positive test, the CDC does not support “retesting until negative” and many insurance companies will not cover repeated tests in this circumstance. The reason for this is that you are likely to continue testing positive for up to 3 or more months. What is critical, is whether you have symptoms of Covid-19 or possibly some other source of infection.
If you have never tested positive and are concerned that you have been exposed, it is best to quarantine to protect others (even if you have no symptoms) and wait until day 5 after exposure to be tested, while maintaining the quarantine.
If you have never previously tested positive but are now symptomatic, we can certainly test you, although the results may be conflicting. In this situation maintaining quarantine to protect others is paramount until you have been tested and the result is available. Also keep in mind, that while Covid-19 is by far the most prevalent current community infection, there are literally hundreds of other viral illnesses which could be responsible for your current symptoms. Strep throat, pneumonia, upper respiratory infections and to a lesser extent, influenza, are still prevalent at this time and can be the source of your symptoms or illness.