Thank you guys so much for the help. After hunting around for a while the other day, I found ALL of the eggs that had been missing from the last few days in a chicken-made nest behind a shed. Although I'm not quite sure why everyone would hide their eggs, I just wanted to let you know the eggs...
I'm not quite sure about molting; most of their feathers seem to be right. Maybe our Rottweiler scared them, because they try to eat his food which he is very protective of, can chickens get scared out of egg laying?
My 4 hens have all been laying quite well up to around a couple days ago. They laid 4 eggs a day, but sometimes bringing the egg count up to 5 or 6. But around two days ago, all egg production stopped. It didn't even dry up, it just stopped. As in the day before we got 4 eggs, and the day after...