Stretch marks on my

So the past couple weeks or so, I've noticed I've gotten stretch marks on my breasts. They're like a bright reddish-purple color. They're on both breasts, on the sides by my arms, starting from the middle of the top of them down around to about the middle of the bottom of them. Mind you, I wasn't blessed with bigger boobs, either. I wear a C cup but with a little padding in it.