hmmm how did you hurt it doc?
i havent pulled a muscle in a while but ive never had bruising when i pulled a muscle sounds like maybe a tear especially if there is pain over the

tuberocity or whatevers its called on your shoulder.
If the supra isnt damaged and it hurts when you do upright rows i would assume the sub but im not doctor but just motion brings the shoulders back a little like a row so again i would assume the sub.
Let us know what happens maybe an MRI?