The American actress, 43, stepped out with what appeared to be a (very small!) bump, hidden under a black coat, and according to rumours, has cleared her work schedule ready to start a family (although it might just be that she can't bear to film another rom-com, no?).
According to Grazia magazine, Jen also avoided the booze and fancy seafood at her own engagement party.
A source told Grazia: "They had a margarita bar, but she didn't go near it, opting for water instead. It was so unlike her and didn't go unnoticed. She was also picky with what she ate, and didn't touch the huge sushi platter, which is one of her favourite foods."
The celebrity press is divided over the rumours. Star magazine - those lovely people who apparently photo-shopped a bump onto Kate months before the official royal announcement - are running a cover with the headline screaming: JEN'S PREGNANT!, while blogger to the star Perez Hilton says she absolutely isn't expecting.
Still, at least the lady herself can see the funny side of us all getting in a flap. She was game enough to take part in the below advert for posh water brand, Smartwater, showing her hiding a grown-up son at home and keeping her triplet pregnancy a secret!