I have eggs at day 7 in the incubator. They have a questionable fertility rate, as they are from my neighbor's chickens. She estimates 60% fertility based on what she sees when cracking them, but I wanted to give it a shot. During my last hatch, I saw a lot of clear veining at day 7. But when I candled this batch, all I can see is a very small air cell at the top, followed by a moving dark mass in the middle, and totally clear at the bottom. These are light colored eggs, easy to see through. I'm leaving town, and have the chance to pick up more eggs, but I don't want to unless I have room in the incubator. Any thoughts? I know I shouldn't give up on them just yet.