Hello and welcome to the flock. Follow the advice of the experts here and all should be well. Congratulations on your new flock. It seems the indoctrination to chickens always involves some sort of issue for many of us. It's like jumping into a deep pool headfirst. No better way to learn.
Also, if I missed it I apologize, but what are you feeding your birds? Many here like to go from grower / starter to an all-flock due to the higher protein levels. Calcium on the side in the form of oyster shells, always available, separate from their feed. Layer feed just doesn't seem to have what it takes to produce decent shelled eggs. Best of luck.