The 30-year-old Gift of Forgiveness author was all smiles as she and Pratt enjoyed a brisk ride around Santa Monica, California, one day after news broke of her pregnancy.
Schwarzenegger was dressed casually in gray leggings and a white pull-over sweatshirt. She accessorized her look with a baseball cap and sunglasses. Pratt, 40, was dressed in all black, except for his patriotic face covering. The couple were joined by Schwarzenegger's father, Arnold, on their bike ride around the neighborhood.
The pregnant star has been keeping as busy as she can be while self-isolating. Schwarzenegger showed off her baby bump on Friday while enjoying a walk outside with her mom, Maria Shriver.
ET learned on Saturday that Schwarzenegger and Pratt were expecting their first child together.
"Chris and Katherine are extremely happy to be pregnant with their first child. The couple knew going into their relationship that having kids together was important to them, so when they found out the news they were extremely happy," a source told ET.
"Although Katherine was busy promoting her book in the beginning of her pregnancy, she now has time to be at home and get things ready for when the new addition arrives," the source added. "Chris is so excited."
Schwarzenegger's soon-to-be bundle of joy will be her first child, and Pratt's second. The Jurassic World star is already dad to 7-year-old son Jack, whom he shares with ex-wife Anna Faris.