I've been trying for the last two months to hatch eggs that my pekins have laid. I have a male mallard, and I see him on top of the female pekins . . . and the next day, I grab her eggs, crack one open to see if it's fertile . . . and it is, then I put the other ones in my incubator, wait a couple days-a week . . . Candle them, AND THEY HAVEN'T GROWN. This has happened about four times. Is it to early in the year for ducks to hatch or what?? HELP, PLEASE!