41 y/o female with pain in upper part of left side chest that comes and goes and under armpit. Should I be concerned?

CP...yes! To me, CP is CP until otherwise ruled-out (for a heart attack). If you haven't seen your md & had an ekg, do it! women present differently than men. If you have a family history of heart attacks, it's even more urgent to see your md. He will probably want a cardiac stress test, blood, & an ekg. Do you smoke? Have high bp? High cholesterol? Diabetes? These are very important to know. See your md!