I an hatching eggs and they are on the 12 day and they are just black clouds inside almost all the eggs I don't know in that's normal or what please help!
On day 12 you should be seeing veining. I don't think those eggs are fertile. Either that or your incubator is way off. Either way they are not developing and won't hatch. What temp and humidity are you running?
Oh, and in the future you may want to post questions like these in the incubating and hatching section, where most of the hatchers hang out. This is the diseases and injuries section, and people in here might not be able to help you. You'll probably get answers faster if you post there instead of here