I need a bit of advice. I set duck eggs (Mallards) under my broody and ended up with one viable egg so when the eggs reached 8 days I put chicken eggs under her and got rid of all the duck eggs that were not viable. Well today she gave up and jumped off, so I grabbed the eggs and put them in the incubator. The duck egg is supposed to hatch tomorrow. When I candled the duck egg there was a shadow in the air cell. Upon further observance there is a crack that run the entire length of the egg and kind of spiders on the small end. Is it ok to leave it in the incubator and see if it hatches or is it unlikely that it is good now?