cresteds can lay infertile eggs--sometimes females will lay a clutch or two when they reach sexual maturity (and before being put with a male) and sometimes the first clutch they lay after being put with a male is infertile. the dimple is most likely a sign that the eggs are too dry--they dimple as they lose moisture. definitely incubate them regardless. often times a fertile but dimpled egg will fill back out once it regains moisture from the incubation material. good luck with them!