Most of the older incubator instructions call for cooling the eggs, most of the new instructions just talk about temp, humidity and turning the eggs, is cooling necessary? I purchased one dozen mail order eggs, they shipped 14, when received 3 were broken, candled the remaining 11 eggs, I could see no air sack in the eggs and not much of the yolk. I did let them rest small end down for two days. Now after 14 days in the incubator the eggs that I assume are fertile are getting a dark mass like my local eggs are doing, but the air sack is very irregular and almost covers half the egg, the local eggs the air sack is normal for the 14 day period and I am sure will hatch but I don't know about the mail order eggs. Should I pull them or see if they will hatch? This is my first time with mail order eggs.