There have been 2 other fertile eggs that I opened and there was one dead embryo that had begun devloping (lost it around day 6). Another I opened around day 9 because the egg was severely cracked and I feared Gretta, by sitting, would open it up and it would get all over theother eggs. So I do know they are fertile.
You've all given me some things to think about. While I don't think any but the first one was an early quitter, as they look like normal day 18 (and so on) candled eggs with the air space and all, I'm just wondering if they are going to be stillborn. Does that happen often?
As for the overly large eggs, I do have one in my fridge. I will open it up when I get off work tonight because now I'm really curious!