"The couple is keeping things very hush hush but their friends and family are super excited for them," a source told website Just Jared, which broke the news. Another insider added, "Sophie has decidedly been choosing outfits to wear on and off the carpet to accommodate her changing body."
The Jonas Brothers singer, 30, and 23-year-old Game of Thrones star first wed in a surprise ceremony in Las Vegas in May 2019.
They had a larger, more formal celebration in France the following month. They have been together since 2016.
When talking with the Sunday Times last year, Turner said the couple briefly split for 24 hours and called it "the worst day of our lives."
"For a second we both had cold feet, then 24 hours later we were both, like, 'Never mind,'" she revealed. In the same interview, the X-Men: Dark Phoenix star credited Jonas with helping her address mental health issues.
"He was, like, 'I can’t be with you until you love yourself, I can’t see you love me more than you love yourself.' That was something, him doing that. I think he kind of saved my life, in a way," she shared.
The Jonas Brothers will kick off a residency in Las Vegas in April. Turner is starring in a new Quibi series Survive. Neither star has commented on the pregnancy reports.