Hi Mitchell,
(Just as a side note - I haven't posted in about six months. Hi again everyone!).
As has been said, everyone is different in how long it takes them to finish growing. I'm 17, and wear a size 10-10.5 men's shoe. Of course I'm one size too large to fit comfortably into all the ladie's boots and shoes I like (which go up to an 11, not a 12), but I digress.
If you have been the same size for several years, that could indicate that you are close to, if not finished, growing. How tall are you? I have had the same shoe size for about 5 years, and I reached 5 foot 6 between fifth and sixth grade (I was rather small before then...needless to say I felt rather awkward for a few years). I haven't grown anymore since then, but I don't mind - with heels I'm about average height. I just wish my feet were smaller, even by just one size.
I sprained my left big toe a few weeks ago and got an x-ray, just to make sure I hadn't fractured anything. The doctor could see from the x-ray that my growth plates had closed up, so this is my basically permanent shoe size. I suppose you could make an appointment and have an x-ray done, if you really want to know, but I'm fairly sure insurance won't cover it unless the doctor orders one for medical reasons.
-EdwardianEra