JimBo,
When I get to the end of my air and feel a bit tweaky, I always blow the air out into my cheeks and puff them out then in and back 4 to 6 times. The recirculates the fresh air in my mouth and throat down into my lungs and I can taste the stale air as it comes up into my mouth. I am sure the extra O2 one gets is pretty minimal, though it should help and gives me something to do so quiets the mind a bit and calms the ego. You might try this to help you relax. I would do this 2/3 of the way thru a static or dynamic a bit before I would get contractions. Good Luck
When I get to the end of my air and feel a bit tweaky, I always blow the air out into my cheeks and puff them out then in and back 4 to 6 times. The recirculates the fresh air in my mouth and throat down into my lungs and I can taste the stale air as it comes up into my mouth. I am sure the extra O2 one gets is pretty minimal, though it should help and gives me something to do so quiets the mind a bit and calms the ego. You might try this to help you relax. I would do this 2/3 of the way thru a static or dynamic a bit before I would get contractions. Good Luck