So I've been incubating some duck eggs and I'm worried about one of them. There was movement and distinct veins for all of development until it grew big enough to fill the whole egg. Now I can't see any veins because most of the egg is dark and sometimes I think I see movement, but it could just be my imagination. The air cell is growing, so I've been holding out hope that it's still alive, but I really can't tell. I'm new at this, and could really use the opinion of a veteran at this. I'll attach pictures below, so let me know if they're not good enough to tell anything. Thank you!