It is a little hard to tell at three weeks. I'd wait till they're about 5-6 wks before really trying to sex them. You could however look for roosterish activity such as chest bumping or dominant behavior.
Aw, I love Polish! I had a Houdan once, but she got sniped by a bobcat. :/
Pictures would really help. If you could get full body pictures, and pictures of comb/wattles/heads.
I would dig a moat around my house and fill it with water.
WWYDI you lived in a secluded village stuck in 1872, constantly terrorized by unknown beasts in red hoods?