Teen Mom 2 Announcement: How Did Briana Tell Her Loved Ones She Was Pregnant?

Plus, find out how soon-to-be big sister Nova reacted to the news

Briana's Teen Mom 2 story began during tonight's season premiere -- and the brand-new cast member's journey toward becoming a mother of two will be featured front and center. While this episode showcased Briana in her second trimester -- and visibly showing -- how did she tell her loved ones off-camera that she was expecting?

"The first person I told was my sister [Brittany]," Briana recently told MTV News (before Stella Star's arrival), explaining that it was "super shocking" to learn she was avec child with a new beau named Luis. "I was picking her up from the airport; she had just come back from a road trip. And she looked at me, and she said, 'You look so different.' And I'm like, 'Oh God, she knows.'"

Eventually, Briana told her sibling -- and Brittany immediately showed her support. Then they came up with a plan to tell their mother Roxanne.

"It was still scary because they had not yet met Luis, so I was like, 'Hey, I'm dating but also I'm pregnant.' It was really intense. My sister ended up telling my mom over a phone call, and I was sitting next to my sister.'"

While Roxanne was initially surprised, the MTV grandmother -- like Brittany -- immediately lent her support.

"They most help out with Nova, if I can't do it. I'm very thankful for them," Briana explained.

And speaking of Briana's firstborn -- how did the little lady process the news?

"I don't think she completely understood. I don't think she gets that there's a little baby coming," she revealed.

How will this pregnancy affect her relationships with her family and Luis? Be sure to keep watching the fifth mama, and her clan, every Monday on Teen Mom 2 at 9/8c.