No weight difference

So, I’ve been trying to get into shape for the past year and a half. I’m 16. Anyway, so I’ve DEFINITELY noticed a visual difference that I like a lot:) plus I feel better. I feel a lot better and stronger, but the thing is I’m still the same weight!!! I know everyone says the number doesn’t matter but I’m just wondering why. Any ideas why? Did my weight just move around or something? Did muscle replace maybe?