What Causes Pain In The Shoulder Prior To Onset On Menstruation?

I have right shoulder blade pain that shoots down thru my arm. Slightly feverish. Started when i got my period 2 days ago. Taken tylenol aspirin doesnt lessen pain. I am 45 years old. Slghtly over weight. 185 5 9. I would get lower back pain usually and headaches prior to menstruation.