Hello. I am a 15 year old girl who has a lump in my right breast . It has been there for a while, and I have had this checked out before. My diagnosis was that this lump was just a water filled cyst . Recently, my right breast has begun to swell , and I feel extreme pain to the touch of it. I have also noticed that the cyst is bigger. My left breast is not tender, and I finished my menstral cycle over a week ago. Is this cyst anything to be worried about? Should I get it checked out again?