Pulse ox monitor is reading between 88-90 but I'm not feeling worse

I (32f) will have been sick for two weeks as of tomorrow. I went to a walk in clinic yesterday, they said my blood oxygen level was 92 and if went any lower I would need to go to er. They sent me for an xray, but said won't get results until tomorrow. They said I likely have pneumonia ad started me on two antibiotics.

Later that night started getting blood in my urine too. Great, one of the antibiotics I'm on should help against that but I am planning to talk to doctor about it when they call with xray result.

I have a finger pulse oxygen monitor at home too, it's by equate if that matters. It's been reading between 88-90 with a heart rate around 113 pretty much all day but the thing is im not having a harder time breathing than yesterday. My lips aren't blue, I'm not dizzy or disoriented, I'm just really sick and tired like I have been for weeks. I'm sure there's an error rate of 1-2% on these devices so potentially could be at 92. I did try it on my son and it read his as 100%

My insurance is a high deductible plan, I really don't want to go to the ER and sit for 6 hours for them to say their device reads at 92 and come back if I get worse and that'll be $2000. Should I just monitor for symptoms and disregard the device? I am not having any chest pains BTW.

The only pre-existing conditions i have is pcos, and I am overweight. No other heart and lunch or otherwise that I know of.

UPDATE: I went into the ER and the admitted me, my ct scan was not conclusive (probably because I struggle to hold my breath for it) but the d-dimer test was 6.05 (normal I guess is .50) which indicates a high probably of a blood clot. I donhave pneumonia in both lungs and they have me on 3L of oxygen, with 2L I was still only floating around 94-95. So definitely good that I came in. Undetermined how long I will have to stay since I'm dependent on the oxygen, and they haven't decided if they will do a repeat ct or another test to try to confirm the possible clot.