Cellulite?

I’m 15 and I’m fairly thin. I eat pretty well and I exercise often. But lately my legs just look swollen? Not fat but just swollen. And there are ALOT of dimples on my upper thighs and butt. ( they show normally without me having to press on them). I’ve seen people much larger than me without dimples when they are normally standing. I wanna know what this is... is it cellulite or something else?

My body:

Height: 5’6

Weight: 120lbs

Body fat: 19.4%

Muscle: 36.7%