I'm 33 weeks and still wearing the same size in thongs every day--if anything, I think my butt has gotten a little smaller/more toned. Did your panty/undie/thong size change, and if so, when? Was it because of your belly or your butt or what? (I have heard I should buy bigger ones I don't mind tossing for post-partum, but at this rate I'm thinking I just use old ones I already have...)