Can a 15 yr old kid carry a blade?

ok so i have a blade its all black and the blade part is about three inches i dont plan on ever even using it but i do carry it around for protection i dnt wanna get in trouble with the law or sumthin thts why im asking im not sure if its a switchblade or a like a pocketknife or sumthin you dont have to press a button for it to come out thiers like a lever on the side