Nikki Bella was ''miserable'' in her engagement before she broke up with John Cena.

The 34-year-old professional wrestler called time on her romance with the 'Blockers' star just weeks before they were due to tie the knot, and in a clip for her reality show 'Total Bellas' which was filmed just after their break-up in April, the star has admitted she wasn't happy in her relationship.

She cries in an emotional teaser for the rest of the show's season: ''I've been miserable and I've been trying to be happy, but I realise there was just such deeper problem.''

Her twin sister Brie then tells her that it is 41-year-old John who has lost out on the ''woman of his dreams'' because of his firm decision not to have children.

Brie tells Nikki: ''He's wanted a very strong career and he has that. Unfortunately to have that, he lost the woman of his dreams.''

Since the pair split, John has since stated on several occasions that he would ''love'' to father Nikki's children, and sources stated recently that Nikki is unsure whether or not to trust her former partner's rapidly changing opinion.

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.''

Instead, 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: ''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.''