I am wondering if I should be worried about one of my hens - it is our first year with chickens. This hen lays blue eggs, so its easy to identify which are hers, and we haven't had one in at least 4 days. We live in the north and the days are short, so that is one factor, and she's not the most prolific layer of the flock to begin with, but I've heard hens can get egg-bound and this can be dangerous. She's behaving normally as far as we can tell - just no pretty blue egg. Should we be worried?