Stretching during sleep

I am expecting for the first time so bare with me.  I have had pressure/cramping now for like five days, for which i have heard is stone cold normal. The uterus is stretching and baby is settling in. Question i have is, sometimes i sleep a certain way and i find myself stretching. In doing so i feel my tummy stretch. You know how stretching feels good. I seem to catch myself doing that in the night. Will this do anything?