MikeB4:
Just checking in to say I am still on planet earth. This week has been a nightmare. My wife tested positive on Monday. The last two days she has been very ill. Today I am concerned about her O2 levels. Her normal is 98% but this morning she has dropped to 91% and the oxymeter beeps a lot. Her BP is ok and temperature is OK. She is coughing a lot and has coughing fits.
91 is lowish. I'd be consulting a doctor without delay.
Not to alarm you, but the thing about Oxygen stats is they can plummet rapidly.
Better safe than sorry, contact your trusted medical professional without delay.