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The MTV mama opened up about her baby on board during TM2 Live!

Kailyn Lowry will soon welcome a third youngster -- and the Teen Mom 2 cast member is revealing some new information about her pregnancy.

"I'm 17 weeks," Isaac and Lincoln's mama told host Nessa during an appearance on the MTV series' aftershow TM2 Live!. But there were some details surrounding this milestone event that she was not prepared to divulge -- specifically, the "mystery father."

"I'm not going to talk about that," Kail said, before adding that she's "not ready yet."

However, Kail was candid about her ex Jo and how the two have addressed this life-changing addition.

"Jo and I were able to address our concerns and talk about things moving forward," Kail disclosed. "Ultimately, he was happy for me and he said, 'Babies are blessings.' So I couldn't ask for a better support system from him."

The same type of interaction did not occur with Lincoln's dad.

"As far as Javi goes, we didn't have a conversation because we clearly don't know how to have a healthy conversation," she stated.

Be sure to keep watching Kailyn and her clan every Monday on Teen Mom 2 at 9/8c -- and stay with MTV News as she prepares to welcome this bundle of joy!