Stretch Marks On My Boobs?!?

Iv been growing breasts for about 3 years now and I have stretch marks around my nipples! Are these normal? I also have them on my thighs, hips, back of the knees and in personal places. By the way, Im 13. I don't want any horrible remarks please! And is there anyway to get rid of them, I don't wear shorts or skirts because it makes me so self conscious!