According to the publication, multiple sources have confirmed that the 39-year-old Mean Girls star is pregnant. A rep for McAdams could not be reached.
The Oscar nominated actress has been keeping a low-profile lately, with the star opting to miss the premiere of her new film Game Night earlier this week.
McAdams has typically been very private about her personal life, but she was spotted holding hands with screenwriter Jamie Linden in 2016, causing a sea of speculation that the two were a couple.
Congratulations to the mum-to-be!