The Black Swan star ignited talk that she may be with child when she was seen with a rounded stomach over the weekend.
But it seems the 29-year-old actress maybe just had a big breakfast and is not going to a mommy any time soon.
"She is not expecting," her spokesperson said.
Mila and Ashton have been inseparable since taking their long-term friendship into the romance zone earlier this year after he split from estranged wife Demi Moore.
Ashton has some parenting experience as he helped raise his stepchildren; Rumor, Scout and Tallulah, during his six-year union with the actress.
Ashton and Demi have been quietly negotiating a financial settlement, according to RadarOnline, in a bid to avoid a "public battle" in divorce court.