Dakota Johnson addresses Chris Martin baby rumours on Ellen in revealing interview

It's been an interesting week for Dakota Johnson, who unbeknownst to herself, turned out to be pregnant - well, in the eyes of the press at least. The star, who is not pregnant, celebrated her 29th birthday last week, and the colour of her balloons - blue and pink - sent the rumour mill into meltdown, leading them to believe that it was a gender reveal party.

Johnson, who has been dating Coldplay frontman Chris Martin for the past year, finally addressed the rumours that she's pregnant with Martin's child. "The only thing I'm pregnant with is a lot of really good ideas," she said yesterday, during her appearance on the Ellen DeGeneres show. "But not any babies."

"It was my birthday, and there were balloons that happened to be pink and blue... and so then I was pregnant," the actress told Ellen, noting that the story was stoked even further when the blue balloons were released into the sky, prompting people to think that the couple were expecting a boy.

"I didn’t know that the balloons were going to be released, they were just in an arch. But I guess that accidentally happened, one of the ends got let go."

"A lot of people congratulated me," she laughed. "[I got] a lot of attention... more than just having it being my birthday!"

This did mean, however, that Johnson had some explaining to do after the fact, "I had to be like, 'It was just my birthday.' Then all the people I didn't invite to my birthday knew that I had a birthday party."

And this was obviously something that Ellen picked up on, jibing "I invited you to mine and you came to mine... I'm just saying."

"I knew [you'd] be with him," DeGeneres said, without mentioning Johnson's beau. "I didn't have your number at the time, which is why I invited him; I knew he'd bring you. Now I have your number and I'll call you directly—and now you have my number, so you could have called to invite me!"

"I didn't invite anybody," Johnson insisted. "I didn't plan it!"

"That is a mighty tight outfit for someone who's pregnant," Ellen concluded, in reference to the Fifty Shades of Grey star's white miniskirt.

The actress has been dating Martin for a year now, after having been introduced through mutual friends.

The Coldplay frontman has two children with his ex-wife, Gwyneth Paltrow, from whom he "consciously uncoupled" back in March of 2014. They have a 14-year-old daughter, Apple, and a 12-year-old son, Moses.

His former wife, Paltrow, wed her fiancée of one year, producer Brad Falchuk, last month. The ceremony took place at her mansion in the Hamptons on Long Island, New York.

Guests included Robert Downey Jr., Jerry Seinfeld, Steven Spielberg, Benji Madden and Rob Lowe, but Martin was not in attendance, instead being a two hour drive away in New York City at the Global Citizen Festival.