Day 19 is early. 21 is normal. Your temp might have been too high and caused an early hatch. It should have been between 97-100 degrees at all times. Too high or too low will affect the chick development.
Your chicks in the eggs are making so much noise... Chicks can "peep" for 2 days before they hatch (that is what the "air hole" in the egg is for). If it lasts more than that, or if they seem weaker, ask yourself this:
Is there any crack or hole in the eggs that they are getting more air through?
The egg shells might be too thick and the chick is having problems. Or, they may not have been turned regularly while developing and their head is not in the right position to crack the eggs. I have seen this a number of times. The chick should crack the egg somewhere between 3/4 and towards the large end of the egg... if it is half way or closer to the small end of the egg, the chick may be in trouble.
If you see a crack or hole, you can try this:
First, make the crack or hole bigger by taking a pair of tweezers and CAREFULLY peeling back the shell. DO NOT tip the shell up so that the back side punctures the inner blood vessels. Try to lift it straight up! DO NOT initiate the hole or crack... if the chick has not started it from the inside, it is NOT ready or not healthy enough to hatch.
There are two inner layers... the white one needs to be peeled back just enough so the air gets in. The red/yellow layer is the blood vessel layer. Do not break this layer. If you see blood oozing out, you may have broke the inner layer. If this happens, you have to do an emergency hatch-out because the blood could suffocate the chick. To do this, follow these directions quickly but calmly....
If the chick does not hatch after the initial "air hole" or appears weaker - give it a few hours to try - or if you accidently broke the blood vessels... then take a hard blunt object (I use the back side of the tweezers) and calmly "Peck" at the large end of the egg, such as the chick would have from the inside but you are doing it from the outside.
Gently lift off the egg shell on the large end. Find the hole the chick made and gently peel first the white layer, then the blood layer away from his face, Use a blunt object (such as the back of the tweezers) to do this... you want to "push" the blood layer away, not break the layer. You can break/peel the white layer. Keep working on it until his head is free and then let him push the bottom half of his body out (this may take minutes or hours). I explain why later...
If you break the blood vessels, you have to put pressure on it and try to stop the bleeding. If you cannot do this while it is still in the egg, then gently pull the chick out. If you see a yellow bulge OUTSIDE his belly, then he was hatched too soon.... The chick 'Pulls in" his belly/intestines just before hatching. If only a little bulges out, you can put pressure on his belly and help push the little bit that is left. Do not push too hard, just gently pressure... you may have to wrap him and allow a paper towel to keep the pressure on it, as it may take a few hours for it to pull the rest of the way in. But if there is more "out" than "in", it is almost a sure thing he won't survive more than 2 days and he hatched too soon. If you have followed the rule of not helping him out before he cracked the egg, then there was nothing you could have done to help this chick.
After you have done this emergency hatch, keep the chick wrapped in a clean paper towel. You may have to change the towel a few times if the chick was bleeding. Wrap him tightly with only his head sticking out, like he is still in the egg. Put the whole thing back into the incubator, or at least under a heat lamp where you regulate that the temperature stays between 80-100 degrees. Leave him until he has gotten himself free from the paper towel and is fluffy and running around. The reason for this is that the chick needs to "fight" to get out of his egg/paper towel. The "fighting/pushing/stretching" is what makes the chick strong and will help him stand.
I have done this hundreds of times when my hatch does not work right. I usually save more than I lose by this procedure. When they are not hatching on their own, intervention is sometimes the only hope they have. But DO THIS ONLY AS A LAST RESORT.
Let me know how things work out.
