I have a Std. Cochin that went broody so I let her and added some of the EE eggs to her. She had eight eggs. I let her set a week ago. I put food and water in front of her and she seemed good. This morning she was on the nest and when I went to check her at 4:00 she was off. Eggs don't feel warm and there is a new one in the nest - I marked the ones to hatch. Is someting wrong or will she return? If not then what? How long will the eggs be ok?