I have a dilemma here. I had about 42 eggs in a still air incubator. All are at least 30 days old. I have it all written down. I've broken apart at least 15 with 5 that were still alive. The yolk was about the size of a dime which leads me to believe they were still developing. The dead ones were the same or term and not hatched. If the incubation period is 26-28 days then what is going on? How long should I let these go before I discard them all? I was able to hatch 6 live ones since last week. Do any of the Guinea breeds have a long gestation than 28 days? I have two pied, 5 classic colored, and one white.