Running help me lose weight?

I know a size 6 is an average size for someone my height (5'4) but I'm 14. I feel weak and I have really bad stretch marks on my thighs. My doctor said I just need to lose a few pounds and they'll go away. I also HATE my size. I want to love my body and I want to feel stronger. Also, I'm doing this to be better at tennis and judo. So if I run everyday will I lose weight by the end of summer? for a mim. of 30 minutes?