The Lizzie McGuire star released a shot in which she appears reclining back on a chair holding her burgeoning stomach.
The 24-year-old leans over to kiss her husband Mike Comrie in the image resembling a scene between Tobey Maguire and Kirsten Dunst in the Spider-Man movie.
Showing off the black and white moment on her Twitter page, she told followers it was from her set of "precious preggo pics", before changing it to her main picture.
She later added: "Glad you guys like my new pic! Much love to all you guys."
With Duff due to give birth to her first child soon, Comrie recently retired from his professional ice hockey career.
The NHL player released a statement saying: "My career has afforded me a series of phenomenal opportunities to play and become friends with some of the greatest people I have ever known and some of the greatest players who have ever played the game."
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Watch the Spider-Man kiss scene in the video below: