Ameraucana is the true breed. Hatcheries and stores and often breeders will use the miss spelling such as Americauna, Americana, Ameracauna, and so on to make you think you are getting a purebred when you are actually getting a mutt. Often times they will even use the correct spelling of Ameraucana when they are just selling Easter Eggers.
Also Ameraucana's only come in a very specific set of colors; your's not being one of them. Nothing wrong with Easter Eggers though! You have yourself a veyr handsome guy! Also Ameraucana's have very specific features such as a peacomb, beard/muffs, and slate legs. Here is a few Blue Wheaten Ameraucana boys I used to have as an example. Ameraucanas also have very little (if any!) wattles.