Something about that snake tells me it's not a corn. The black on that snake is way too black (looks like the entire saddle is deep dark black with no borders). Background color is strange, and the head scales are strange too, that rostrum scale is way too big for a corn.
I'd check with the place you got it from and ask them, or if they don't know it'll just be more hunting I guess. It's a nice looking snake though, I wouldn't mind having one like that.
It almost looks like a young black rat, or even perhaps a fox snake.
Look for pictures on line with terms Black Rat, and Elaphe Obsoleta (btw, black rats get huge, 6 ft avg).
-13mur 6