No flame intended bro, but you're 17 and have been working out for a while? How long do you consider a while? BTW 5'11" and 190lbs is very respectable at your age. I imagine you don't have a lot of extra BF either. Just to give you an idea, when I was 17 I was 5'8" and I wieghed 150lbs.I started lifting when I was 18 (naturally) and by the time I was 21 I was 5'10" and 195lbs (I don't know where the extra 2" came from). You obviuosly have a strong genetic advantage over me so just imagine what you could accomplish if you fine tuned your diet and training!! This may not be what you want to hear but if you wait 3-4 years before picking up a needle I'm sure you will go very far. BTW I didn't do my first cycle until I was 34 (3 months ago). The guys here are A-1 and you will find a plethora of information on diet and training if you interested in our help. Good Luck.
Pete