[TheAtomicBlade]

Hey,
Just something to remember, puberty is different in different people. You may not have shown a huge increase in muscle mass or facial hair and thats fine. Sometimes you just put on height. Its a common enough factor (i know many males who didn't have the "puberty" hit till they were 18, but they had grown taller, and when they started working out, shown muscle gain).
You could discuss it with your doctor, if that would make you feel better. Really, don't worry too much. Stay healthy, eat clean, exercise etc. and you should be OK