Mila Kunis and Ashton Kutcher have started telling friends about her pregnancy.
The couple have yet to publicly confirm the happy news they are expecting their first child together, but sources say they have started letting those close to them know, as Mila's bump is starting to show.
A source told E! news: "They kept it a secret as long as they could. But obviously, she's started to show so it was just a matter of time in recent days."
Mila, 30, and Ashton, 36, have been very private about their relationship since they got together in 2012, which is very different to Ashton's high profile marriage to actress Demi Moore - which ended in 2011 - when they would pose for pictures and openly discuss their personal lives on Twitter .
Another source said: "She is so private she probably won't ever talk about it - at least not publicly.
"She and Ashton don't want to share this with the world. They've been like that for their entire relationship. Ashton knows what it's like having a very public relationship and doesn't want it again."
Mila has previously spoken about motherhood, saying she is likely to cut back on her career when she has a baby.
She said: "I want to be a present mom. When I was growing up both my mom and dad worked full-time.
"I want to be a producer ... But I also want a life. I want a family.
"Do you want to have a life, or do you want to have a career? Sometimes you can find a happy medium, but in this industry it's rare."