My legt pec has fat on it, while my right is alot tighter?

I am 16 years old, and am well developed. I have been training hard for a whole year, so I am enjoying my results!!! Anyway, when I stand infront of the mirror, it is very noticeable that my left pec droops and I have alot of fat around it, while my right pec is alot more defined. What is the best thing to do? I bench press, dumbbell fly, incline bench press. I REALLY want to define my lower pecs.....