Sore Shoulder In Breast Cancer Is It Possible/probable For A 15 Yr Old Girl To Get Breast Cancer?

Is it possible/probable for a 15 yr old girl to get breast cancer? - sore shoulder in breast cancer

I think I might have breast cancer. I just know I have some examples, and I'm worried.
1. I think I may be small, hard lumps on the right feel
2. I had severe pain during the last week (like a sharp pain on the pain bruising)
3. one side is growing faster than the other
4. I was very tired and on my back / shoulders have been painful lately
5. My breasts are more difficult to achieve

What's happening? I asked my biology teacher last year and said it was a possibility and it could also something like a lymph noid ** or strangely similar.
I asked my mother, and she tld me if I'm still in pain 2 weeks, which I lead my doctor

The only really worried because my GMA just died from cancer and I did not know or is it too late to stop.