I set a double yolker 14 days ago. I just candled it, and I see lots of veins. I comparison to two other eggs of the same age, I think it looks good. I see dark, thick veins and two big yolk/chick masses. Air cell looks good, same as any others I've hatched successfully. It is either barred rock X barred rock cross OR barred rock X white leghorn. I'm crossing my fingers for this one!