There are LOTS of chicks that look like this, it's just the wild type of patterning for camouflage. You should share images and information in your own post if you want help determining the sex of your chick. It will likely be apparent by pattern around 4 weeks of age when it has most of its baby feathers showing.Did the questionable one end up being a roo?? I have one that looks just like that and I’m thinking it’s a rooster for sure.
Hens go broody when you don’t want them to… and won’t go broody when you do. 