Catelynn Lowell has confirmed she's pregnant with longtime boyfriend Tyler Baltierra's second child.

"#it'sofficial #4months @tylerbaltierramtv," the 21-year-old Teen Mom star captioned a black and white photo of her growing baby bump on Instagram Wednesday.

Reports began circulating about three months ago that Lowell, who gave her first baby up for adoption five years ago, was expecting again. Lowell's mother April Stotts actually told Us Weekly at the time that her daughter was pregnant again.

"She was crying when she knew for sure and so I was like, 'Are you happy? Are you upset?' And she was like I'm happy!'" Stotts told Us in May.

Lowell made her reality TV debut when she starred in an episode of MTV's 16 and Pregnant in 2009, when she gave birth to a daughter named Carly. Lowell and Baltierra have had a relationship with their baby girl and her adoptive parents ever since.

Lowell and Baltierra got engaged and appeared on the third season of VH1's Couple's Therapy. However, the parents-to-be reportedly called their engagement off afterwards. 

About The Author: Elizabeth Kwiatkowski
Elizabeth Kwiatkowski is Associate Editor of Reality TV World and has been covering the reality TV genre for more than a decade.