Freestyle Head "Jerking"

After watching a video on my freestyle, I seem to have an upward lift or jerk with my head when I breathe. It appears my head may be a little low in the water (hips are up ok) and when I go to breathe I get this jerking motion instead a smooth roll. I have about 1 + 1/4 goggles out of the water at the top of the breath. I've been all over the map with head position........is there any drills or imagery which could smooth out this? Or is this related more to a potential problem with arm swing and trying to vault over the anchor? thanks