I am incubating 12 eggs. After the 14th day i candeled them all and 1 was not developing so i threw it out.. the other 11 were fine. Ok at the 18th day i took them off the turner like i was supposed to. but on the 21st day none hatched. I waited 4 more days and nothing. so on the 26th day i opened one egg and the chick was fully developed but dead inside it looked just fine except its belly was very squishy and its bottom was really poofed out. What happened to the chicks, or what could have caused this.