The couple announced the sex of their unborn child Wednesday to Us Weekly.
"I was so shocked that it was a girl because I for sure thought it was a boy!" Lowell, 26, said. "Tyler knew the sex before I did. When we did our gender reveal, I was so shocked I almost cried because I wanted a boy so badly. I'm super excited it's a girl now. Since our miscarriage, I just am thankful to get another chance, and as long as it's healthy, that's all that matters!"
As for trying for a boy in the future, Lowell admitted she and her husband have "talked about trying again."
"We definitely want to have a boy, but if God only wants us to have girls, then that's just what it is," she said. "It will be a houseful of ALL girls! Poor Tyler!"
The MTV couple announced last month that they were pregnant again after losing a baby to miscarriage last year. The couple, who wed in 2015, share 3-year-old daughter Nova and placed 9-year-old daughter Carly up for adoption in 2009.
At the time of the big announcement, Lowell shared with Us Weekly, "The big news is that we are expecting our rainbow baby. This baby is our rainbow after the storm. I'm super excited.
"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 continued. "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."
The couple is clearly in a better place now, but fans of Teen Mom know that the last year has been incredibly tough on the two. After the miscarriage, Lowell admitted she was experiencing suicidal thoughts, and checked herself into mental health treatment to recover for several months, leaving Baltierra to parent 3-year-old Nova alone.
In Monday's episode of the MTV series, the 26-year-old dad admitted to friends he was beginning to resent his wife, even after she returned home.
"I'm gonna be really very honest. I feel like I'm not too happy right now. I'm identifying that I feel pretty miserable," he said. "When does it ever turn around though, where you know what, Cate, I need you to actually do this for me? When is it ever 50/50?"
He continued: "I'm saying this is what I need. If you can meet those needs, awesome. If you can't, let me know. I don't want to waste any time. Let me get out of here. Marriage is a b—."
We're glad the couple was able to work things out.
Teen Mom OG airs Mondays at 9 p.m. ET on MTV.
Photo credit: Getty