So I didn't catch my hen start setting this time. It's been about 2 weeks since I took note of it. I candled the eggs today and most appear solid inside and have a air sac. I would have liked to move her to a separate pen, but, I'm afraid it's too late and she might quit setting. How do I guesstimate how much longer I have till they hatch. And how do I know if it's been too long?