finch eggs

Question
About 21 days ago I noticed the first egg in my Society finches nest. I don't know if the eggs were fertilized, never witnessing mating, and she laid them after us buying her and her mate only 2 months ago. The eggs were a light brown color and now are a darker gray with a white spot at the top of one. It has been so long, I am wondering if these eggs are going to hatch. How much longer do I wait, and if they are not fertile, what do I do, the parents take turns coming out, so one bird is always in the nest. Do I just take the nest out?  

Answer
I doubt the eggs are fertile. The best way to tell is to take an eggs out and break it open. If there is a blood spot, it was fertilized, if not, it isn't.
What the birds are doing is taking turns sitting on the eggs. This is normal behavior and I wouldn't worry about it if I were you.