different size pecks! how to equal it out?

richtries

I've been training for about a year now and where i used to play tennis the left side of my body is much stronger. I thought it would even itself out but its just getting worse. i'm not to bothered about my biceps etc., but think my chest looks a bit odd. is there anyway i could even it out/build up my right peck? My gym instructor advised me to give up weights on my chest and do press ups but i'm trying to bulk up so? I've been thinking about concentrating on using dumb bells and using lighter ones on my strong side(left)/heavier ones on my weak side(right), what do you think?