Hi

as far as can see x ray is ok.but re dislocation probably that was dislocation, or maybe sprained generally saying injury. Then, hard things such bones, which u can see them in x-ray looks fine (my opinion). But soft tissues (muscles, tendons,ligaments,etc) serranding the joint are injured (overstretched, torn, bruised), and cant see in xray. Those (overstretched, torn, bruised), at beginning make immflamation (hot,tender, redish, pain, swollen etc) as a natural defensive reaction after (overstretched, torn, bruised).

When u get well (i think) the most important is analising why the shoulder is prone to injury, and implement proper rehab.

all the best