@catelynnmtv / Instagram 1 / 6
@catelynnmtv / Instagram 1 / 6

Get the nursery ready because the baby is coming!

"Teen Mom" star Catelynn Lowell showed off her growing baby bump on her Instagram account on Nov. 21, looking happy and very expectant.

RELATED: Where are they now? "Teen Mom" and "Teen Mom 2"

"Baby girl almost 33 weeks," the MTV reality-TV star captioned the selfie taken in front of what appeared to be a bathroom mirror. She cradled her growing belly while wearing a fitted black-and-white top and blazer.

RELATED: Former MTV stars: Where are they now

Catelynn and boyfriend Tyler Baltierra are expecting their second child together. The couple gave their first child Carly up for adoption shortly after she was born. The high school sweethearts arranged for an open adoption, which allows them to visit with Carly twice a year.

RELATED: Flashback: 'Teen Mom 2' star arrested ... again

Once engaged, the pair called off their wedding in July 2013, but have remained together. She recently raved about Tyler on social media.

"My man is the best man," she captioned an Instagram photo of the twosome last month. "He is the world's most amazing father love him with all my heart and soul."