So I got these for my period overnights to use with cloth pads, however I can't use them currently as I am 7 months pregnant.
I'm normally 110-115lbs and bought an xl, they look to be the same size as my adult size 5 underwear, these unlike the ones I bought for postpartum are lower on the hips and are a younger cut, as they should be because they're big girls sizes. My postpartum ones go up to my belly button, these sit where standard cotton bikini sit and will work wonderfully after I am back to my regular size.
I am normally a size small or med in bottoms and these feel like they will be the right fit to keep my pads from sliding around

Hope this helps!