Nikki Bella revealed the big epiphany that kept her from marrying John Cena during a recent episode of Total Bellas.

On the May 27 episode of the E! reality series, the model admitted she was struck with a bad feeling while trying on wedding dresses ahead of their engagement party, where Nikki and Cena announced their plans to wed in Napa Valley.

"So the engagement party is here. I feel so overwhelmed," the 34-year-old supposedly said to the cameras. “I honestly feel like I’m about to have an anxiety attack. I just feel like I’m on this roller coaster of emotions and I feel like I’m going to explode. It’s just all too much for me.”

It wasn't until the celebration was interrupted by Brie Bella, who revealed that Nikki's brother JJ Garcia and his wife would be expecting their second child, that Nikki confessed that her not having a baby with the WWE star is what's been keeping her from being as excited to marry.

"I just know deep down I want a baby," Nikki started in a confessional, "I just … I want to be a mom and I feel like I can't live the rest of my life not having one."

Dia Dipasupil, Getty Images

“I don’t even know how to start except, um, I guess just like for some reason since Birdie’s been born and I’ve spent a lot of time with Birdie, it’s just brought up these feelings of really wanting to be a mom," Nikki lamented to Cena in another moment of the episode. "I don’t know if I would regret it later on in life if I wasn’t."

In the past, the 41-year-old former wrestler has been forthcoming about not wanting children, a condition, Nikki has admitted, that's been difficult for her to grasp.

"Nikki and John truly love each other, but they will never have the same view on a perfect future," an insider told Entertainment Tonight. "Nikki has always dreamt of having a family of her own and John does not want children and that was the main cause of their break up. They are both dedicated to their careers, but Nikki wants more than just that."

Back in April, Nikki and Cena announced their decision to split after six years as a couple. In a statement concerning their breakup, the pair revealed they called off their engagement and May 5 destination wedding.

The estranged lovers were recently spotted grabbing a coffee and taking a walk through San Diego's Mission Hills district last week.

John Cena and Nikki Bella through the years