The gorgeous Tron actress announced in October that she is expecting her first child with actor/comedian fiancé Jason Sudeikis.
On Saturday (2 November), she was snapped out and about in sunny Los Angeles wearing comfy jogging bottoms and a loose fitting white T-shirt that gave us just a hint of bump.
She showed off her fab complexion by going make-up free and kept her brown locks tied back.
Olivia may have been dressed in work out gear and carrying a bottle of water but apparently she had to skip the exercise for the day, tweeting: "A cancelled workout class is the ultimate grownup snow day."
Later that night, the 29-year-old joined We're The Millers Jason courtside at the Staples Centre in LA to watch the Lakers playing.
The engaged couple looked thoroughly loved up throughout the game, with Jason keeping an arm around Olivia and her resting a hand on his.
It was a busy weekend for the pair as the following evening they hit the black carpet in LA for a star-studded bash.
Wearing a floor length black gown that covered her bump, House star Olivia looked drop dead gorgeous at the LACMA 2013 Art and Film Gala honouring Martin Scorsese.
Olivia met comedian/actor Jason during an appearance on his US sketch show Saturday Night Live back in 2011. They announced their engagement in January this year, after Jason popped the question over Christmas.
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Copyright: Vimeo / Weiss Eubanks