I would wait for other changes expected for roosters - hackles, saddle feathers, sickle feathers and crowing (not all that crows is a rooster) or if an egg pops out, you've got a hen. In the interim, if you really like this guy and don't want to eat him or someone else to eat him, spend the time finding a back up home for "him." There are some surprise chickens out there that don't seem to follow the rules (the late or early bloomers in the bunch). Send some updated photos in a few weeks and it should be easier to confirm by then. Usually by 10-12 weeks you know (although I still have a Wyandotte I'm on the fence about - she has a "back up home" just in case).