Catelynn Lowell and Tyler Baltierra are expanding their family.
On tonight's all-new Teen Mom OG, viewers received a big surprise when the couple announced that they are expecting baby No. 3.
It all started when Catelynn dressed daughter Novalee Reign up in a shirt that read "I'm going to be a big sister."
"Why do we have that shirt?" a confused Tyler asked. "Because she's going to be a big sister," Catelynn added.
What came next was shock, aww and a whole lot of hugs once the realization hit that a third child is on the way.
"How many did you take?" Tyler asked before Catelynn confessed that four pregnancy tests all confirmed she was pregnant. "Oh my gosh! You're a fertile myrtle."
It appears the news was captured by MTV cameras around Halloween as tonight's episode included several cast members visiting local pumpkin patches with their kids.
As fans of the pair know, Catelynn announced earlier this month that she was leaving home to get treatment at a facility for undisclosed reasons. The announcement came two weeks after she completed a six-week program.
"Well they say third times a charm... I'm going back to treatment people for 6 weeks to work on my trauma and getting on different meds," Catelynn tweeted to her fans. "THANK YOU @TylerBaltierra I LOVE YOU SO MUCH!!!!! You are my light!! And nova you are my sunshine #KeepTalkingMH."
And while Tyler has been keeping his wife's journey private on social media, he has been able to show his support.
"I am SO PROUD of this woman! When you have been fighting your whole life to survive...it doesn't just make you a survivor...it makes you a damn WARRIOR!" he recently wrote. "I love you babe @CatelynnLowell."
Teen Mom OG airs Monday nights at 9 p.m. on MTV.