The MTV reality star and long-time boyfriend Tyler Baltierra are thrilled to be expecting a baby girl in the coming months – and Catelynn has been keeping fans updated on her progress via Instagram.
Yesterday, she uploaded a beautiful silhouette shot of herself on a Pensacola, Florida beach, giving us a clear view of that bump!
She added the caption: "Can't wait to meet my little girl."
Another picture shows a pink T-shirt-clad Catelynn cuddling up to her sister, who is placing a protective hand on her bump.
Catelynn and Tyler rose to fame on MTV's Sixteen and Pregnant, followed by its spinoff show Teen Mom. Cameras followed the young couple as they made the difficult decision to give their first child up for adoption as they thought it would be in her best interests.
Catelynn had been just 16 when she fell pregnant. They still see their daughter Carly and her adoptive parents.
Now, the couple both work and have their own home meaning they feel ready to welcome a child to their family.
But their joy was marred slightly this week thanks to negative comments posted online which forced Tyler to write a lengthy Instagram message praising Catelynn and telling her to ignore the haters.
Tyler told Catelynn she looks "beautiful" and she should remember: "I love you, that little girl in your tummy loves you and you're absolutely angelic!"
He said: "Any woman who can carry a child at 16 and have the strength to do what you did for her is GORGEOUS inside AND out. Any woman carrying a precious bundle of joy is beautiful to me. Regardless of what these pathetic low life people have to say."
He added to the "rude people" who had criticised Catelynn: "This woman would do ANYTHING for anyone, care for you when you're down, clothe and feed you if you needed it. You know I feel bad for the people who don't know her because if you did, beauty is all you would see in this strong woman."
Concluding, he told Catelynn: "Love you babe, more than this world, and can't wait to meet our precious daughter."
Catelynn posted the message to her own Instagam with the simple caption: "He's the best."
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Stars who welcomed babies in 2014:
Copyright: Rex Features WENN/Matthew Taylor/Daniel Deme/Josiah True/Matthre Taylor/Joe