How do i get rid of the stretch marks on my thighs?

okay so for over a year now i have had some stretch marks on my thighs. last year i gained like 3 pounds(i was under weight, so i was instructed so by my doctor) but now i have stretch marks. now i am not a fat girl, i am 5'9'' and i only weigh 118 pounds okay. but i am trying out for my school cheerleading squad for next year so i need to get rid of them pronto!!!! i know that they take time but it has been a year. about 2-3 weeks ago i began using palmers cocoa er formula for stretch marks, they are better but what would you suggest to help get rid of them by july at the latest??