Is it possible for a preteen girl to get breast cancer?

I know that people say the chances are extremely low, but I want to know if you think I should tell my relatives so they can get me a mammogram. When I was 11, this little mole formed under my left breast. I'm unsure if it would be classified as ON the breast; it's just below it. For a period of about six months, this mole grew and became raised. It's dark brown, symmetrical, about a quarter of a centimeter large (estimation), and a bit raised. For a few weeks when I was 11, there was a patch of red, itchy skin below this mole; this persisted for nearly a month. The mole doesn't seem to have grown since then, and the itchy patch went away. I am now 13 and thinking that it seriously could be breast consider; initially, I shrugged it off as a "nah.." but as of now I'm more dubious and worried. I deem myself healthy; I'm not overweight, exercise regularly, and eat very well. This is not the only mole on my body; I've also got one on my neck that's been there since I was 5, along with a few more and a bunch of freckles along my arms and upper torso. My skin is fair and insufferably prone to sunburn. My father has several large, lumpy moles along his face, and has many freckles and moles along his upper torso, as well. So, what do you conclude? Should I keep quiet about it (because it would be terribly embarrassing and seem senseless to my family if I said, "I think I have breast cancer"), or should I tell someone about it? Thank you in advance!