I have a batch of 5 true ameraucanas, 4 were cockerels and 1 pullet ( bad luck!), the boys all looked exactly like yours in the comb at 8 weeks, the girl had no color at all and barely a bump of a comb. This is TYPICAL for pea combs, and if your bird is a typical pea combed chicken then you have a cockerel :-(
Yours may be one of the exceptions so give her/him some time mine crowed at 9-10 weeks for confirmation lol
Yours may be one of the exceptions so give her/him some time mine crowed at 9-10 weeks for confirmation lol