JOYSHAPERSlip Shorts for Under Dresses Anti Chafing Shapewear Short Thigh Slimmer Panties for Women with Lace

I'm in-between a US size 18 and 20, should i go up a size or do these fit a size 20 well? The sizing shows 16-20 then 20-24...kind if a big difference

Are the white see-through?

My hips measure size m and my waist size xl, i normally wear a l, what size would you order?

what is the waist level? I need it at my navel or below.