Blac Chyna was forced to cancel two public appearances due to morning sickness.

Rob Kardashian and Blac Chyna

Rob Kardashian and Blac Chyna

The 27-year-old star - who already has three-year-old son King Cairo with ex-boyfriend Tyga - announced last week she and fiancé Rob Kardashian are expecting a baby together and it seems pregnancy has begun taking its toll on her as the couple pulled out of a scheduled event in Atlantic City, as well as another in Los Angeles.

In an Instagram post he has since deleted, Rob wrote early on Sunday (08.05.16): "Chyna really wasn't feeling well last night, which fell over to this morning."

And Chyna apologised for missing the events and promised to reschedule.

In a message which she has also deleted, she wrote: "Sorry LA & Atlantic City.

"I really wasn't feeling well LAST night which fell over to this MORNING causing us to miss our flight ,, Rob and I want to apologize for missing these events for we were looking forward to them as well but new dates are coming soon! (sic)"

Atlantic City club Pool After Park complained about a "no show" from the 29-year-old sock designer and his partner.

An instagram post read: "Uh Oh a ChyRo No Show!"

And Rob's former stepbrother, Brody Jenner, slammed the couple for failing to honour their commitment.

He posted: "That's what you guys get for hiring those 2...Sorry not sorry.(sic)"

He later deleted the comment.

The loved-up couple - who got engaged last month following a four-month whirlwind romance - announced their happy news on Friday (06.05.16), despite initially planning to do it on Mother's Day on Sunday, because they were worried a member of Rob's family would leak the secret.

A source said recently: "The family found out in the last couple weeks. Rob told everyone separately. They didn't have a big family meeting or anything like that."

However, the showbiz clan - including Kim Kardashian West, Khloe Kardashian and Kris Jenner - weren't overly thrilled when they were told the news as they were hoping the pair's relationship would crumble before long.

The source said: "When Rob started dating [Chyna], it was like, 'Okay, this is a phase.' And when they were talking about the engagement, it's like, 'But it won't last.' But now that there's a baby coming, everyone in the family knows that this relationship has permanence. Even if it doesn't work out, they're going to be co-parents of this child forever."