there are other ways than radiation to check see a doctor you are never to young to make sure you dont have cancer i may be 19 and male but iv watched many in my family die from it young due to being to late to treat it or for instance having breasts removed 2 of my grandmothers have had that procedure they don't mind it but at your age id think you would but whatever the case get it checked out. A.S.A.F.P.
Usually they are not recommended for casual screening until you are in your late 30's or early 40's. mammograms expose you to radiation so it's not something you want to do regularly early in life unless it is needed or you have high risk factors. Go to your doctor and have them examine you, they will be able to determine if further testing is warranted.