The Twilight star's fiancée Dominique Geisendorff is pregnant, according to Just Jared.
The couple were photographed celebrating Independence Day and some have alleged that Geisendorff had a "tiny baby bump".
Gigandet and Geisendorff already have a 3-year-old daughter, Everleigh.
Gigandet previously starred in several episodes of The OC, while aside from Twilight his movie credits include Easy A and Burlesque.
He recently signed up to appear in Catherine Hardwicke's new movie Plush.