O2 fluctuation questions

Age 39 Sex F Height 5'6 Weight 240 Race White Duration of complaint <2 hours Location USA Any existing relevant medical issues Pulmonary Hypertension, new diagnosis, waiting on right heart cath. Hx of submissive saddle PE. Current medications Ozempic, Eliquis, Sertraline, Buspirone, Levothyroxine Hi all, have a recent diagnosis of Pulmonary Hypertension. My family is currently on vacation at a ski resort. Knowing we would be at higher elevation, approx 11,000ft, I brought my pulse-ox and some of the canned Oxygen to have on hand. Questions: my pulse ox at home seems to vary very little, like just a couple of points up/ down. Since being here, my lowest was 83 (immediately after arrival). After a few puffs of 02, it's fluctuating between 88-94 which feels likea big jump. Is my pulse ox crap, or can it go up and down like that? felt dizzy and weak earlier, are there other signs I need to watch for to tell it's low?