Billie wore the glitzy costume for the Only Way Is Essex series finale party, which was Prince and Princesses themed and filmed yesterday (30 March).
The mum-to-be covered her bump in blue sequins and completed her looked with a fancy two-strand chain around her forehead.
Posting the pictures online, Billie simply tweeted: "#selfie."
In January, Billie announced that she was expecting her first baby with her long-term boyfriend Greg Shepherd.
Soon after, Greg proposed to Billie in the Maldives and the couple later revealed that they are having a baby girl.
In last night's episode of TOWIE, Billie's sister Sam threw a baby shower for her and the girls and their pals all feasted on tea and cake.
Looking very proud and excited about becoming an auntie, Sam was seen placing her hand on Billie's growing bump. Aww!
Celebrities who have announced baby news in 2014:
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