If you already have shoulder problems I'd advise you to fix them now before worrying about how big they are. Make sure you balance your pushing movements (all forms of benching and overhead pressing) with enough pulling movements (work for upper back and lats) and internal rotation with external rotation. Don't fall into the trap of mostly working what you can see in the mirror as this leads to muscular imbalances that will make your shoulders worse. I'd also suggest you check out Eric Cressey's three part shoulder saver series if you've never seen it. Just google it. Great stuff.