Shoulder pain during pullups

I’ve got this pain in my right shoulder for the last week now. It only hurts when I try to do pull-ups. I can do shoulder presses, side and front laterals and feel no pain. Even if I do lat pulldowns I don’t feel it, but when I do bodyweight pull ups it hurts bad enough that I can’t even pull myself up. Does this sound like a rotator cuff injury? Any help before I go to the MD is appreciated.