I'm only 15. I can feel bumps or lumps in both my breasts in the same places, but I have no clue if that's normal or if I should worry. I'm too scared to tell anyone. You should not worry or be scared. Breast cancer at your age is very, very rare.
Some girls get cysts that come and go with their menstrual cycles.
The best time to examine your breasts is about one week after your period has ended. The best place is while you are in the shower. You can go around the breast in ever-increasing circles or start from the center and go out like spokes of a wheel all around the breast. You may need to gently squeeze the nipple to make sure there is no discharge either. Lumps or bumps in the same places in both breasts may just be glandular tissue.