Hi all! I picked out a shear, form fitting wedding dress for my wedding in September. The bridal shop put me in this special ribbed bra to try on dresses that cost around $70. Do I actually need this bra or any bra? I don't usually wear dresses so I don't own any strapless bras. I definitely have small boobs but the dress is already padded. Also can I get away with just wearing no line panties underneath or do I need some kind of special slip? Here's a picture of trying on the dress with the special bra at the bridal shop

and here I am trying it on at home over my normal underwear (unpadded bra):

This is all pre-alterations fyi. I don't know anything about lingerie and I'm sort of overwhelmed by the options out there (shapewhere, slips, thongs). what did you ladies do on your wedding days? Any advice?