We started incubating 6 call duck eggs on 12-23. One never developed the other 5 veined. Out of those there are 2 that have dark spots about half the size of a dime that seems to be staying in the same spot the last couple of times we candled and the air sack looks large and not shaped right. The other 3 you can see moving in the shells. Do you think the two with the dark spots are quitters and should we remove them at this point? Thanks so much!