HOW BIG SHOULD THE AIRSAC BE ON DAY 19 OR 20??? MY EGGS ARE STARTING TO DANCE AROUND AND WE HEAR TAPPING AND CHIRPING...SO WE ARE GETTING READY TO HATCH...BUT WE HAVE SOME THAT ARE NOT QUITE AS FAR ALONG...AND THEIR AIRSACS SEEM REALLY BIG...ANYONE HAVE PICS OF DAY 19/20 AIRSACS?...THANKS FOR YOUR TIME AND HELP IN ADVANCE...