UpSpring High Waisted Postpartum Underwear Tummy Control Shapewear Briefs for Women, Black/Nude, Small-XXLarge

I wore a size 8/10 prior to getting pregnant, but my hips have gotten so wide. What size should I be looking at?

Are these American sizes?

Is this the C-panty?

What is the recommended size for 8/10, because i see two different answers on here from "upsring baby" ? one is saying s/m and another is saying l/xl