Don't worry about it, you're still growing.
I had those too when I was younger. I didn't have too many and they weren't very large, but they were definitely there.
I didn't think anything of it or apply anything to try and minimize them. They faded away rather quickly and now they've faded so much that they're pretty much gone... not noticable at all.

If you want you can try applying different oils or cocoa butter.
I've never tried either, but apparently they work. I don't know about the oils though but there are a bunch of different posts on this board about stretch marks, so you can easily find those and that should help figure out which kind of oil works well and whether or not you want to try it.
I still think you shouldn't worry because they'll probably fade soon enough.