I have this now and then, and I know it's part of the jerks. Suddenly out of nowhere, I take a deep in-breath, like a gasp. It's hard to describe because all our breathing is pretty much involuntary. But this is different. It's a big, deep, quick in-breath and feels like a jerk almost. Has anyone had this? I've had it off and on from the beginning and it happens only when I'm laying down on my back.