keep working.
you look decent for 17. most kids your age can get to that from working out normally though because your bodies are very responsive to many forms of training. it looks to me like you should focus a little more on your shoulders traps and back. do some pullovers on a bench with moderately heavy weight to help widen your chest a little. if you're going for size and strength, eat everything you can put in front of you as often as possible. with little fat on your body and at your age your metabolism is in high gear so any fat you may gain can be easily lost. supplements are a good idea, but can be costly especially for a teen. any type of weightgainer would be beneficial. I like the prolab N-large 2 and champion nutrition heavy weight gainer. Anyway, these are just my two cents, take it or leave it. But keep up the good work.