I am going to strongly suggest that you do nothing. I am positive that this is a slight glitch and in a few days you will be getting very nice eggs. Producing and laying eggs happens without any human intervention MOST OF the time. I have had chickens for decades and have NeVEr had a chicken with the problem of not being able to lay eggs.
It does amaze me on here how many people seem to treat this problem, but then I realized that no one posts when eggs just come naturally, so it seems to be a bigger problem than it is.
Oyster shell, or calcium in layer feed, or eating egg shells, is a slow long term health aid. Most diet is. Go ahead and have a bowl of oyster shell out, it won't hurt anything, and they will nibble on it as needed. They are not going to eat a lot, and a lot of the time, they are not going to eat any of it. They eat it as needed.
Calcium is a big part of any animal, the body has multiple ways of supplying the calcium needed for daily use. Diet is only one of the ways, and not that big of one. No need to force feed it.
Mrs K
