Kate Hudson was determined to keep the news out of the headlines until she had passed her first trimester and remained at home in Los Angeles to prevent the paparazzi from learning her secret.
But the actress sparked concerns for her health among her friends, who thought she was ill.
Kate Hudson tells Britain's The Times, "My friends all thought I was depressed, because I wouldn't leave the house. But I didn't want anyone to know for a long time.
"I was just hoping that all of a sudden I could show up somewhere with a belly. But, of course, you're somewhere in L.A., and somebody says something, and it ends up somewhere. And here we are."
The blonde beauty also opens up about the pitfalls of carrying a baby, admitting: "I'm pregnant and I'm really sick! I babble a lot. I forget words. And how to put sentences together. I just give up!"
The baby will be Kate Hudson's second child; she already has a son, Ryder, from her relationship with ex-husband Chris Robinson.