While leaving, Johnson removed the sweatshirt she had been wearing to show off her black sports bra and matching leggings, her flat and toned stomach fully on display and dispelling any notion of a possible baby bump.
In photos seen here, the 50 Shades of Grey star completed her laid-back look with a brown tote bag, sunglasses and a messy bun.
It had previously been reported that Johnson and Martin were expecting a child together and had thrown a gender reveal party over the weekend, but the bash was ultimately revealed to be a birthday party.
Johnson dispelled the rumors herself during an appearance on The Ellen DeGeneres Show on Thursday, with host Ellen DeGeneres joking, "That is a mighty tight outfit for someone who's pregnant."
The audience didn't seem to catch the reference, and Johnson noted, "See? They don't even know what you're talking about."
"Well, this is Thursday, but Monday it came out that you were pregnant," DeGeneres explained. "So, I'm just saying...How's that going?"
"Well, the only thing I'm pregnant with is a lot of really good ideas. But not any babies," Johnson responded before detailing the reason the reports surfaced in the first place.
"There were balloons that happened to be pink and blue...and so then I was pregnant?" she said of her birthday party. "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. But a lot of people congratulated me."
"Now maybe you want to get pregnant," DeGeneres joked, "because you get so much attention."
"A lot of attention!" Johnson admitted. "More than having it just be my birthday. 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.
Johnson and Colplay frontman Martin were first reported to be dating in October 2017. After the pregnancy reports surfaced, Johnson's rep confirmed to PEOPLE that they were false.
“Chris lives in Malibu and Dakota seems to love hanging out there," a source recently told PEOPLE of the couple. "They occasionally go for dinner with friends, but mostly have friends over at home. They go to the beach together, and walks around the neighborhood. They seem to enjoy sharing a quiet life. It does seem they are getting more serious.”
Photo Credit: Getty / Steven Ferdman