Gymcoach can probably give you some solid ideas, but if the rest of you is growing, it's going to be hard to tell if your shoulders are growing or not. As your arms, chest, etc. get larger, the shoulders are most likely growing, but you just can't see it.
Also, what rep range do you use? If you're focusing on heavy weights with low reps, you might try switching it up for a few weeks and use a 8-12 range or even a 12-15 range. Change is always good. If you're been using moderately heavy ranges, switch to heavy weight and less reps (at least for your compound lifts like the military press or seated shoulder press).
Switch it up and see how it goes.