The effect you are describing is “viral load”; the degree to which a virus is present in the body. And while this is an indicator of how infectious you are. It is especially important for people with HIV to see if they are “safe” or need their medication adjusted.

However, an at-home test will not be a good indicator of this. These have too many variables such as the site that was swabbed, time delays from the various biological functions, how well you used the kit and even variability in the kit itself.

To properly test for viral load, a blood test should be used. I worked with a company that tested for viral load via expelled breath, and while this was a good indicator of infectiousness y/n, and was faster than a PCR, it was not more accurate.