I've been doing a bit of weight training recently, and I've noticed that my right pec is slightly smaller and less muscular than my left. I guessed that my left side was probably my naturally weaker side, and so had to work harder to keep up with my right ( keeping the bar balanced when bench-pressing etc.), therefore making it a little bit bigger. Now I'm wondering if maybe having a little bit extra weight on the right side (2.5kg maybe?) will help even up my two pecs? Is this a good idea, or should I just stick to keeping the same amount of weight each side of the bar?