Why does my blood oxygen level drop from a 95 to below 70 when I start to move around from a sitting position and feeling good. I move from a sitting position to walking, making my bed, ((any movement) and it drops drastically and I start panting and try to catch my breath. I turn my oxygen gauge up to 5-6 but I still have this problem. Once I sit my level goes back to the 90's within 2-3 min. So frustrating.