Rob Kardashian and Blac Chyna constantly argue on camera

Rob Kardashian and Blac Chyna’s reality show is driven by their constant arguments.

The couple – who got engaged in April after just a few months of dating – are chronicling their preparations for the birth of their baby on new E! docuseries ‘Rob & Chyna’ and despite having so much happy news to celebrate, they reportedly spend a lot of their time squabbling and yelling at one another.

Production sources told TMZ they fight over a variety of issues, from the reclusive sock designer’s weight, to posts on social media, to money and fame, and very few things are not filmed.

And the tension between them has only been exacerbated by Chyna’s pregnancy.

The pair are being filmed five days a week, for up to 13 hours a day.

It was claimed recently that Rob, 29, had had second thoughts about doing the show – but producers are not unhappy as his indecision has only caused more conflict with his girlfriend, making for "really good TV".

The show was said to be "in crisis" recently as Rob had been skipping filming and worried the programme would "compromise" his relationship with the 28-year-old beauty, who also has son King Cairo, three, with ex-boyfriend Tyga.

However, a source claimed Rob was simply going through "one of his mood swings" and his behavior – including deleting all his Instagram posts – was "nothing new".

The insider said: "He is just going through one of his mood swings, which is common for him. But he is still filming.

"He goes through his dark periods. He gets depressed and doesn’t want to really do anything, doesn’t leave the house. It got better for a bit when he first started dating Chyna, but he’s in a rut now. He’ll snap out of it."