my eggs starting hatching yesterday 12 light sussex eggs and a mix of eggs. the first one that hatched came out fast and fine within 3 hours then the others started hatching all well and good until it came out of the egg and all so far have like a hole/ball umbilical cord thing hanging out where the chicken lays a egg? its a mess i tried putting a few back in with a cotton bud but it pops back out? ones whole insides was draging around behind it until it burst in my incubator? i have 1 fine looking chick and 2 others with a very lite case of the last it hasnt came out? i froze the others for a quick death. any ideas why this is happening?