I know this may be a little late but that all sounds normal to me. When the air sac looks "broken" that is the internal pip, the chick will break the membrane surrounding it so that it can get it's beak into the air cell to breath. Usually you will see one or two bumps on one side of the air cell, that is the chicks beak. Sometimes you will be able to see them breathing. At this point, you shouldn't be messing with the eggs unless you truly believe they are in distress (you'll know after a few hatches).
The blood veins will be visible until just prior to the chick actually hatching. One of the reasons there is so much time in between internal pip to hatching is because the chick is absorbing the blood vessels and yolk, basically just preparing to enter the world.
The chip on the outside is the external pip, the chick does this when it starts running out of air in the air cell. And the thin white sheet is just one of the membranes inside the egg. There are two, one that surrounds the chick tightly, and another that basically sticks to the inside of the shell, you will see bits of the outermost one once they pip externally and zip through the shell.
Hope this helps, and I hope you had a healthy chick hatch!
hes socute he's sprinting around falling over! By the way THANKS SO MUCH for helping I really liked you helping. Bye! Thanks a lot!!
