My two arms are 2 different sizes. Reason being, because my dominant arm is my right? I also feel i do enough 1 armed exercises, especially since changing my routine a couple months ago. I do power week 1, rep range week 2, and super set week 3.

My bicep part on the outer side of my left seems way smaller than my right. Everytime I do bi's, I just feel there isn't a connection between me and them. I've hurt my left shoulder starting back lifting 3 or 4 years ago, and seems like ever since then, I do 3 less reps than my right, regardless of the workout. What the hells wrong? Possibly be bicep tendon?