What Causes Breast Pain And Muscle Tightness?

hey doc....am asking a question related to breast cancer. i am 30 yrs old and from few months i feel small pain wen i touch my breast. it's not exactly pain but feel tight muscle...i am sorry i don't have right words ,,i hope u'll get what am trying to say . i can also see a new mole on my left breast. i am scared ..please help