One oximeter shows 98 spo2 reading and another shows 94 which is correct? covid positive patient 50 year old ?

All readings have to be correlated with circumstances and actual symptoms in order to be meaningful. While both values appear normal, clinical status and further readings in dynamics will help clear the differences and assigning accurate readings to one or another, would continue checking with the one believed to be more accurate.

Pulse ox readings can vary depending upon exercise, coughing and the device. Key is the trend; is it dropping, staying stable, or even improving as it likely parallels effects on lungs