I had a hen free ranging and found her on a clutch of 18 eggs. Rather than have her Fox bait I decided to hatch the eggs myself in an incubator. I have one egg starting to hatch, but never have done this before my anticipation of a new arrival makes me want to help it along and crack the shell more to help it out. fundamentally i know that thats wrong. how long does a normal hatch take from start to finish?