Question about body fat

Anna
I'm almost 19 so I guess you could say puberty has come to its end for me, but lately I've been noticing something weird. I used to store fat on my legs and butt, not on my stomach at all. But recently it has switched, I am gaining weight because I quit taking the birth control pill several months ago, and all of it seems to go to my stomach. How is it possible that my body just stores the fat somewhere else all of a sudden? Has anyone else experienced this after puberty?