ET spoke with the actress at Daily Front Row's Fashion Los Angeles Awards at the Beverly Hills Hotel on Sunday, where she teased how she plans to celebrate her 40th birthday on April 19.
"You're not gonna know about any of it," Hudson joked to ET's Keltie Knight. "We were just talking about that in the car. [It will be] fun."
Inside the show, Hudson's close friend and jewelry designer, Jennifer Meyer, presented her with the Entrepreneur of the Year award for her popular athleisure line, Fabletics.
"It's funny, because for the last five years of my life it's what I've spent most of my [time] doing other than raising my kids, so it feels really great," the mother of three explained to ET. "I think this company, Fabletics, has been one of the more rewarding things I've done in my life because when I started, the success was amazing -- like a dream for a startup -- and then it hasn't quite let out."
"It just keeps growing," she added. "We're collaborating with all kinds of different people, and next thing you know, it's most of your work and your life. So it feels good to be here accepting this."
Hudson was just one of many celebrities who stepped out for the swanky event on Sunday. Guests, including Lady Gaga, Courtney Love and Adriana Lima, were treated to glasses of Chateau D'esclans Cotes De Provence Whispering Angel Rosé, FIJI water and Kronenbourg 1664 premiere beer of France before taking their seats for the awards show.
Gaga was in attendance to present her good friend and hair guru, Frederic Aspiras, with the Hairstylist of the Year award. The singer gave a passionate speech about all the ways Aspiras has picked her up while she's down, reminding her how to be confident and "strong."
Watch the video below to hear highlights from her speech.