question: Hi. I've been experiencing chest pain for about 31/2 weeks now. It's on the left side near my left breast. I've been  battling breast cancer since January 2010. It was in my left breast. I can't tell if pain is in breast or around the left lung/heart. I started taking Cymbalta about 31/2 weeks ago for joint pain/arthritis related to Femara, my daily cancer medicine-an anti-estrogen-right around the time chest pain began. I'm suspecting the Cymbalta at this point. Your thoughts?