If the eggs have not been incubated you can check for fertility by breaking the egg and examining the yolk. A white dot means not fertile and a bullseye means fertile.I have various different places for them to nest, such as under their house, several boards leaning for them to lay under, and different piles of brush. I have no idea if the eggs are fertile. How do you check?
http://www.backyardchickens.com/t/16008/how-to-tell-a-fertile-vs-infertile-egg-pictures