My left pec is bigger than my right and I think my arms are the same. Seems to me my left bi/tri is bigger than the right. That's weird b/c I'm a righty. I would think it'd be the other way around. My fiance notices about the pecs, but no one else has said anything. I can't really tell just by looking, but they do feel different. I don't know what to do for it either. I don't care. I can live with it.