Undies!

My go-to daily legwear are leggings. I always wear thongs with my leggings, but I recently have been having some discomfort in my vagina area. My doctor cleared me and said it wasn’t an STI, yeast or BV. She said it’s probably from the soaps I use and wearing “fancy underwear like thongs” (her words). So I switched to vajayjay-friendly soaps but now I need some help. What kind of undies do you wear with leggings? And if they’re thongs, then are there certain ones that are better? Thanks!