Shoulder pain

Hi, I've been working out with FB for over a year but for the last week or two I have been experiencing shoulder pain after upper body workouts. It's a constant pain and a bit of a numb feeling that goes down my arm. Should I take a for a few weeks from doing upper body workouts? Is this possibly caused by wrong form? Of so, how would I know what I might be doing incorrectly? Any tips would be appreciated! I don't want to lose the progress I've made so far. 😥