Is my butt still going 2 grow?

I'm 13, so when I was 11 I used to be really chubby and had like normal butt but when I got my period and turned 12 I lost weight a lot, but whenever I wear jeans, short or something my butt is sooo flat like my butt got sooo thin and skinny! but when i wear VS pink yoga pants my butt looks normal/average. and i always try to work itand tone it but not butt, will it still be growing?