The 34-year-old professional wrestler split from her fiancé in April, just weeks before they were due to tie the knot, after she began having doubts about whether or not she wanted to marry a man who didn't want to have children.
Since their split, John has changed his stance on becoming a family man and now says he wants children with Nikki, and whilst the 'Total Bellas' star has been firm in saying she needs more time to think, sources now claim she isn't convinced by John's comments.
A source said: ''Nikki doesn't know if she trusts John still. Is he really saying he wants to be a dad just for her or does he truly want to have children? The more attention this is getting, the more pressure Nikki feels.''
The brunette beauty is said to be ''figuring out what's best for her'', and spending time with friends and family in order to clear her head.
The insider added to People magazine: ''Nikki is trying to figure out what's best for her right now. She's trying to focus on herself by spending time with close friends and family and staying committed to work. She's not the type to just jump back into it.''
Meanwhile, 'Blockers' star John, 41, recently claimed he would love to be a dad and father Nikki's children, despite having long been opposed to the idea in previous years.
He said: ''I would love to be a dad. I realise very much that I have been steadfast in saying that I don't want children.
''I dedicated my life to my work, and now I'm realising that there is life, and life exists, and it's beautiful, and I think part of that is being a parent.''