I've got 2 hens laying and have gotten 13 eggs thus far. My chickens are brown leghorns. All the eggs have been perfect, but small. Should the eggs get larger, or does this breed just lay small eggs? Or does egg-size vary from chicken to chicken? I know some leghorns lay larger eggs (they come in "small, medium, large and extra-large" in the store), so I wonder if mine will eventually lay some larger eggs?