also, if you have a still air incubator, the temp is different in different parts of the bator. Just yesterday I cracked open a couple of eggs that did not hatch along with their clutchmates, and they were quite alive, just a couple of days behind their mates. I am learning as i go, and I think from now on I might leave the outside rows on the turners empty and see if it makes a difference. Hope this info helps. Leave them a few more days, you might get a surprise.