There's a stain on my new tennis skort!! I've only had it for a week and we're not supposed to get them dirty! I was being extra careful too since it's the school's stuff.

I don't know how I even got the stain or what it is. It's by the lower butt area so it probably happened when I sat on the ground. Anyways, I used non-chlorine bleach and cold water in the washing machine. The stain is still there. Anyone know what to do? (By the way, I'm soaking it in non-chlorine bleach and water solution right now)