I'd rather feel like my stomach was groaning than be overwhelmed door the sensation that there's something in my head trying to burst it's way out of my skull.
Stomacheache because when I have a headache I eat two Tylenol and go to sleep, but when I have a stomachache I don't want to eat anything and am in too much pain to go to sleep.
At least I can physically verplaats when I have a headache, and it's not the sort of pain that makes me bend over the whole time and makes my face screw up strangely. :L