Yes male guineas do buckwheat. Not nearly as much as the females though. One of them, Summer got us really confused. He thought he was a girl for a long time. he eventually figured out how to make the girl noise at 5 months and did it plenty of times, randomly, at least one burst every fortnight for I've lost count how long but then he stopped and started mating the hens. Now it's laying season here in Australia and he is nearly a year old and definitely a boy. A few of the other cocks have buckwheated once but it was just a fluke.
How old is your guinea? If you got him as a baby in August that's a bit early to tell. Do you live in the USA? I think it's non-laying season there you should be opposite of me but anyway they don't lay until at least 5 or 6 months and in laying season. Aussie laying season is Oct-Mar and you might have to look up what's yours. How is he going? Any more girly sounds?