First of all, this is my first time at trying to hatch eggs. And these are Mallard ducks, not chickens, but I couldn't find anywhere else to ask. I've got 6 eggs from our young Mallard pair. I've had them in the incubator for 7 days. I candled them at 4 days and 1 definitely had the spider veins near the top of the egg. I just candled it again at day 7 and I don't see any of the spiders and the egg appears to be very dark or cloudy throughout. Do you think something has happened to it, or is that normal to see at day 7? Thanks for any help!