The TOWIE star, 24, wore the cute LBD on a night out with the girls, including sister Sam Faiers and Ferne McCann.
Posing for two selfies at home before heading out, one in her bedroom and another in her kitchen, Billie's rounded tum can clearly be seen in the stylish outfit.
And despite being 22 weeks pregnant with a baby girl, Billie braved towering heels in a bold fluorescent yellow.
Alongside the shots, Billie wrote the messages: "Out for dinner with the girls ... #babybump.
"Ready for our girlie dinner .. Thank you @HairHutEssex for my lovely blow dry."
Billie is expecting her first child with fiancé Greg Shepherd.
Sister Sam Faiers, 23, also took to social media to show off her rather fabulous outfit.
She told her Twitter followers that she was wearing a River Island leather skirt, Giuseppe shoes and This Is A Love Song top. We absolutely love the look, Sam!
Celebrity Big Brother star Sam has been on a juice diet ever since being diagnosed with Crohn's Disease last month.
Do you like Billie and Sam's Saturday night look? Tell us what you think below!