Sunny and 80s here.
I knew for sure at 2 weeks that 2 of them were cockerels, the other two snuck up on me at around 4-6 weeks. There combs brightened up much earlier, and got much thicker. The wattles were also much more prominent than the pullets by then
Are we talking two weeks that you had them? I have had mine two weeks. I think that all but one was close to a week old when I got them. That one is different then the rest at two weeks old the feather growth is very slow like a roo but small in body size, comb and feet. If they have slow feather growth are they always boys?