Just wait and see until comsb start to develope. The Leghorn combs on the male chicks start to sprout within a month and you can safely tell. I can tell the Black Leghorn chicks at hatching as the pullet chicks are jet black. In some breeds, the size of legs are an indication. The wing feather method will work with some breeds but I haven't found it reliable enough to use. I could never get anywhere with vent sexing, even when the eyesight was much better !