I am 28 year old female who exercises often. My mother has a pulse oximeter and i used it just out of curiosity. My blood oxygen saturation was 99 at rest but when I ran on the treadmill with it for a couple of minutes, it dropped to 86. My heart rate was only about 130. I generally exercise at a much higher level than I did during this test and I am afraid I may be doing damage to my organs without realizing it. Should I see a doctor and what type of doctor would be able to test this for me?