Having pain under left breast area.when i stretch or move or apply any pressure it hurts.no injury,not pregnant or on period.i am 19.cancer?cause?

Cancer unlikely: Breast cancer is unlikely at your age. It is not feasible to provide a meaningful opinion without examining you. If your symptoms do not subside in a couple of weeks or if symptoms get worse, do see your doctor. Have a healthy diet, exercise, drink plenty of water, have safe sex, no tobacco alcohol weed or street drugs. For nutrition: http://www.choosemyplate.gov/. Get HPV vaccine