Proning can increase SpO2 by opening up new air sacs in lung. Oxygen supplementation can increase SpO2.
Otherwise SpO2 reading by pulse oxymetry may fluctuate due to various technical issues like cold fingertip, reading variability.
Regarding medicines, duration of treatment is usually 5 to 15 days depending on which medicine you are taking.
Strictly follow your doctor's advice.
Next Steps
Follow the advice of the doctor who prescribed the medicines