Delicate fabrics - chiffon dresses and skirts. Anything floaty looks lovely. Kimonos or lacey dressing gowns would also work well
Sretchy or clingy dresses, skirts and tops, these help to accentuate your bump. Maxi dresses always look fab
Oversized or loose shirts and blouses
Underwear options, nude, black and white underwear and strapless bras or crop tops (if you’re happy to show some skin)
Footwear - don’t worry too much about shoes, most of the shoot will be barefoot anyway (unless there is a pair you love or you had something in mind)