Covid question for the hive mind if y’all will indulge:

So I went to a small Xmas party Sunday night: eight people including myself. Except for possibly one couple, everyone’s at least had their two shots.

One couple’s son had gone out-of-town Friday night and came back late Sunday, with a fresh COVID infection in tow. The entire family was tested on Monday: both the couple and their other kid who lives there are negative.

Here’s the conumdrum: I’m a little skeptical that the son left the house COVID-free on Friday and came back Sunday night as a plague rat. My understanding of COVID is that:

A) Son could have had COVID for up to two weeks prior to Sunday and only then developed symptoms.

B) The couple could have been asymptomatic on Sunday but still spreading it.

Right now, I’m trying to quarantine. I was supposed to see family tomorrow and Xmas, but as of this writing I’m cancelling all that out of an abundance of caution. Am I worrying over nothing, or should I just lock myself down until I can get a test?

I’m boosted as of almost two weeks ago. I coincidentally have a doctor’s appointment tonight (got switched to teleconferencing), so I’ll bring this up then.

TIA for any help.