They're adorable! I'd give it a bit more time. If their combs turn bright red within the next two or so weeks you'll know that they're cockerels. Love your nails, btw!
Bright red combs and wattles at this stage are pretty good indicators of a cockerel. Females usually redden up close to point of lay. Also, when they get a bit older males will develop pointy saddle and hackle feathers and females will have more rounded feathers. Hope this helps some.