The former TOWIE star confirmed to OK magazine that she and fiancé Greg Shepherd's second child will be a boy.
And she couldn't be happier!
Billie told the new issue of the magazine: "We're in complete shock. Greg and I always thought we'd just have girls and everyone around us put that in our heads, too.
"We can't stop smiling."
A little boy means Billie's sister Sam Faiers' son Paul will have a little playmate! Although Billie has already ruled out calling her son Baby Greg!
When we met up with Billie recently, she admitted the couple had been going back and forth about learning their baby's sex. "Greg really doesn't want to find out but I might do. Last time we knew we definitely wanted to find out."
She had previously told Daily Mail, however, that a baby boy would be wonderful. "I always thought in my head that I'm always going to have girls but now that I've seen Samantha with Paul, I would actually love to have a boy as well," said Billie.
'It would be so nice to experience having one of each but on the flip side, it would be really nice for Nelly to have a sister as well because then it would be kind of like how Samantha and I were."
Billie, 26, announced her second pregnancy in September. She and Greg already have a daughter Nelly, who celebrated her second birthday in June.
"Nelly does, kind of, [understand about the baby]," said Billie. "Sometimes I'll tell her I've got a baby in my tummy and she's like, 'No.' Then other days we'll ask her if she wants a little brother or sister and she'll say one or the other - it always changes! I think when my bump gets bigger, she may understand."
Billie and Greg have been engaged since 2014 but Billie's frequently said they are in no rush to marry.
"We've said 2018 is the year we'll do it because I need some time to get back into shape and get on with organising the wedding, which is going to be even harder with two babies," she told us.
"We're not in any rush to get married. It's lovely, but when you have children, it isn't the biggest thing in your life anymore."
Billie quit TOWIE earlier this year but is back on screen thanks to sister Sam Faiers' reality show The Mummy Diaries, which airs Wednesdays at 9pm on ITVBe.
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