I have 6 chicks that are 18 weeks old. They have not laid any eggs yet. I saw/heard one of them in the coop making some strange noises and it was obvious that she was in the nesting box. The wood shavings were as though she was burrowed down in them. I was sure she was going to produce because of all the noise but there was nothing. Is this common? When can I expect eggs? thanks. New to this .