Hi - Your mom is almost certainly right - nothing to worry about. However, I can tell that you're going to worry anyway! Kudos for being concerned about your breast health, so early in your life; it's a good lesson to learn for later on. I've never believed in worrying; it doesn't produce anything but misery. I believe in action. So, what about if you went and had a physical, and mentioned to your doctor your concerns? You're old enough to have a physical on your own, without your mom; you could speak to the doctor privately. AND you'll learn how to tell the difference between a lump that's normal, and one you should worry about.   In the meantime, please read our Teenage Guide to Breast Development; I think it'll help calm your fears. Good luck - PJH