Pulmonary Embolism Support Group
By far the most common form of pulmonary embolism is a thromboembolism, which occurs when a blood clot, generally a venous thrombus, becomes dislodged from its site of formation and embolizes to the arterial blood supply of one of the lungs. Symptoms may include difficulty breathing, pain during breathing, and more rarely circulatory instability and death.
Has yours been on 94 for a prolonged period of time, or just when the pulse ox is first attached to your finger? Also depends which type you are using, the ones you can buy which are relatively cheap (like the one i have, around 45 - $70) have a level of error - mine is up to 3%.