On Thursday, Lowell shared a new sonogram with fans on her Instagram Story, adding a poll that asked, "Anyone gotten induced at 37 weeks?!?"
Since then though, Lowell has not posted about her pregnancy on social media.
The last time Lowell was pregnant, she suffered a miscarriage in early 2018. She later checked into rehab for mental health treatment after experiencing suicidal thoughts. Lowell and Baltierra announced they were expecting in September, and said it was not planned.
"It was a huge shock at first. We were not planning it, especially after the miscarriage and how I went downhill with my mental illness," she told Us Weekly in September. "We were going to wait a really long time. We were using protection and everything and still got pregnant. This baby just wanted to be here. It was very unexpected."
During a November episode of Teen Mom OG, the couple said they planned to name their baby, revealed to be a girl, Tezlee.
In the middle of the pregnancy, the couple said they were going through a trial separation to work on bettering themselves before Tezlee is born.
"Am I jumping for joy for it? No," Lowell said of the separation on the show, before later adding, "Things that I've been through, when when people separate and say they want to leave, it seriously feels like somebody died. It's bringing up the old wounds from the miscarriage, and that's traumatic."
"I think me and Cate got together super young, and we used each other as survival to drive through this life," Baltierra said of the split during the Teen Mom OG Season 8 reunion. "You just kind of lose who you are as an individual. Who am I if I'm not Catelynn's husband?"
Their relationship has been on the upswing for the holiday season. On Christmas Day, Lowell shared a photo of them at a holiday party together and said she was "blessed" to have him in her life.
"I love you so much [Baltierra] thanks for blessing me with three beautiful girls and choosing me as your wife," she wrote. "I'm truly blessed by you! I love you!"
Baltierra and Lowell have been together since they were teens and married in 2015. They are parents to Novalee, celebrates her fourth birthday next week. They also welcomed Carly, who was adopted by a couple in 2009.
Teen Mom OG airs at 9 p.m. ET Mondays on MTV.