Pain in chest or shoulder accompanied with painful menses can be matter of concern. Painful menstruation is
known as dysmenorrhea. Dysmenorrhea with pain in chest or shoulders is seen usually in endometriosis. However
there are many other symptoms of endometriosis such as low back pain, pain during intercourse,
gastrointestinal symptoms etc. Sometimes acid reflux from stomach can also cause shoulder pain, but as you
have pain only during and before periods so it is most likely endometriosis. You must consult a gynecologist
for proper examination and treatment. Hope this helps you. We wish you healthy life ahead.