This is the different stages mine went through, might help you with what to be looking for.
https://www.backyardchickens.com/a/is-it-a-rooster-some-simple-signs
So it's 16 weeks now? I would be expecting to see the longer skinny feathers on neck and back near tail and a rooster tail forming by this age. Is there any sign of new feathers coming in?
Mine had a definate roosters upright stance by then too.