Hi! I m female in my 40 s. I have a pain in my upper right arm. It has been lingering for about 2 days now. It feels exactly like a flu shot. However, I had my flu shot about 2-3 months ago. I don t think my shot bothered me this much. It s warm to the touch, very localized, and very painful. Throbs, burns, and seems like it hurts much deeper than just below surface. It almost seems a bit swollen. I haven t done anything physical to bring this on either. Any thoughts on what this may be? Thank you :)