'Teen Mom' Stars and Their Kids

"It was a huge shock at first," Catelynn says of her pregnancy.

There's another baby coming to the "Teen Mom" family!

Catelynn Lowell is pregnant, the "Teen Mom OG" star confirms to Us Weekly, and expecting her third child with husband Tyler Baltierra.

"The big news is that we are expecting our rainbow baby. This baby is our rainbow after the storm. I'm super excited," Lowell told the publication. "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."

After experiencing suicidal thoughts following her miscarriage, Lowell entered treatment in November of last year, before leaving in December and going back again in January of this year.

"We were going to wait a really long time," Lowell added. "We were using protection and everything and still got pregnant. This baby just wanted to be here. It was very unexpected."

The two are already parents to 3-year-old daughter Novalee and placed their first child, daughter Carly, up for adoption.

The new season of "Teen Mom OG" premieres October 1 on MTV.