Hailey Bieber shot her new Saint Lauren promotion while four months pregnant with her and husband Justin Bieber’s first child. The model, 27, announced she was expecting her and 30-year-old singer Justin’s baby in an Instagram post on 9 May, and has now reposted a photo from the luxury brand’s Instagram showing herself posing in a strapless belted jumpsuit with a black purse and bangles, to say it came 16 weeks into her pregnancy. She captioned the image: “Shot this four months preggy with little bean in my belly.” Even though Hailey hinted at her due date with her post, it is unclear when pho…