If i'm only 25 do i need to worry about breast cancer?

Maybe: If you have a strong family history of breast cancer, you may be at increased risk. Talk to your doctor regarding genetic counseling, specifically for the brca gene. If, however, you don't have such a history, self breast exams monthly until age 40, then self exams + mammograms yearly, should detect an early very unusual mass for your age. After menopause, risk of breast cancer is age related.

Not too much: You should know your family history and your risks. It would be rare for a 25 year old to develop breast cancer. If you have concerns you should see your physician who can answer your questions and perform an exam.