Will I Be Covered?

OK, when I was about 10-12 years old, I was a little on the chubby side. Now I'm 15, with a changed look. Muscles and all. The only downside is that I developed stretch marks around my shoulders, lower and middle back. I know that is common for weight lifters, and that's not a problem for me. It's just that I want to be a fitness model and I don't know if these marks would interfere with my being accepted by an agency. The question is, are problems like these covered up and forgotten about?