I'm very sure that's a cockerel. At 14-15 weeks old that's a very big and ret comb. The short tail is an indication too. Orpingtons are very slow to grow male specific feathers, that's why you don't see them yet.
If it's doing proper crowing, you got your answer 😉 I know hens can start crowing, but it mostly only happens if there isn't a rooster in the flock and in my experience a hen can never crow as good as the roosters.
When this is said it is a cockerell, just haven't matured with all the male...