I am a first time chicken incubating mama...I have 2 batches of eggs in the 'bator. I batch has been in for 7 days and I candled about 8 of them. 1 egg looks like it just has a yolk in it, 2 or 3 most definitely look like there is something going on( veins, little shadow of something) and a couple look dark, but I can't really see anything discernable. I will check the others later, but the one that looks like just a yolk I am thinking is a dud, no? What about the dark ones?