stretch marks and weight of woman

Kiana • ❤️smyo
Hello ladies. Im 15 and i weigh 120lbs. Just half a year ago I was 98lbs and I'm starting to get low self esteem now that I'm realizing that I have stretch marks at the top of my thighs. Im 5& 1 3/4'. I wanna add that I am in cheer so I have to stretch those muscles a lot. But I also and constantly working those muscles up. I keep making excuses saying that maybe that's why I got stretch marks.. truth is.. my stomach isn't skinny .. I guess It's not either.. (at times🙄). Should I try to loose weight? And any pointers?