After feeling constantly tired for several days, followed by some muscle pain and feeling cold (despite it not being cold around), I thought that maybe I got reinfected with COVID. I had no fever, and no other symptoms (some other family members were not feeling well with fever, and suspected strep). Luckily I had a home BinaxNow antigen test, which I used, and it came back negative (I also happened to take an antigen test at a test location a week earlier, in order to be allowed into a hospital, and that came back negative).
This morning I got news that my daughter, who we were sure had strep due to several days of a sore throat, tested positive for COVID (after strep test came back negative).
I wonder if having the symptoms I had is somehow related to being exposed and my immune system fighting it off (I did previously test for very high antibody levels, though I haven't tested those in a while). @biobook any input?
I am not a doctor, and don't even play one on DDF. I would advise seeing your family doctor.
In theory, all the things you've considered sound possible.
Maybe you had a very low covid infection, so some symptoms, but your immune system fought it off, so no antigen measurable in the binax test this week.
Maybe you encountered covid last week, right after your negative test, hence the symptoms, and also passed it on to your daughter, but easily fought off the virus, so no longer have enough for a positive binax test.
Maybe you do have covid, but the binax test is giving a false negative. IIUC, the tests are temperature-sensitive and the reagents degenerate over time.
Maybe your symptoms relate to long covid, related to your first infection.
Maybe your symptoms relate to one of the myriad conditions that caused tiredness and muscle pain even in the pre-covid era.
Perhaps you want to take a PCR test, to reassure yourself that you're not infectious now to others or, if you are infectious, so that you can isolate.
But mostly I think you should pose your question to your personal physician, who presumably is familiar with both covid and your medical history.