Bella and Cena dealt with a constant tension in their relationship, as the model reportedly wanted to have children one day, while Cena never wanted to be a father.
Since the couple announced their split on Sunday, fans have been revisiting all the highlights of their relationship, including the E! reality series, Total Divas. It was there that Bella, now 34, once took a pregnancy test on camera, believing she was carrying Cena's baby.
The episode aired in 2015. In it, Nikki and her twin sister, Brie Bella, discuss a small irregularity in her menstrual cycle.
"Aren't you supposed to get it when I get it?" Brie asked.
"I'm always on the same time as you," the WWE star said. She gave no consideration to privacy, stating "I had major symptoms, I don't know why I didn't get it. My nipples are huge."
"I actually brought a pregnancy test," Bella said conspiratorially, "because I was not going to do it in front of John."
The sister then went into the bathroom together, Brie accompanying her sister for moral support. Finally, the test came up negative.
"That's crazy that it just says 'no,'" Nikki Bella said. "Could you imagine if I couldn't have wine for the next nine months?"
"You would have been a raging b—," Brie said.
Bella and Cena were only weeks away from the wedding they had planning. It was supposed to take place on May 5 in Mexico until they decided to call it off.
"It wasn't going to be some showy Hollywood, over-the-top glitzy thing," a source told PEOPLE of the wedding, adding that Bella was excited to celebrate her heritage with those close to her.
Cena proposed to Bella at Wrestlemania 2017. When their relationship began, he reportedly told her firmly that he never wanted to get married again, nor did he want to have kids. He obviously changed his mind about the marriage last year, though he never actually went through with it.
"When [Cena] proposed, he convinced [Bella] that he was a changed man," another source told PEOPLE. "And if he can change his mind about never wanting to get married, why wouldn't he change his mind about not wanting kids?"
Both Cena and Bella have posted about the break-up numerous times on social media.