The 34-year-old, who made her name singing classical showstoppers, shared her baby news in a low-key tweet about missing the Valley Aid 2020 concert, which was held over the weekend to raise money for Welsh flood victims.
Church had been scheduled to perform alongside Manic Street Preachers front man James Dean Bradfield but pulled out.
She wrote: “Gutted to have missed it. I’m preggers so I’m airing on the side of caution in terms of (the) virus. It looks like it was a great success. X”
CNN has reached out to Church’s representatives for further comment.
Church is already mom to Ruby, 12, and Dexter, 11, with her former partner, the Welsh rugby player Gavin Henson.
Her latest pregnancy will be her first child with husband Jonathan Powell, whom she married in a secret ceremony in 2017.
Months before their wedding, Church’s representatives confirmed she had suffered a miscarriage.
“Charlotte and Jonny are very sad to announce that they lost their baby. Now is a time for grieving and being together as a family. ‘We kindly ask everyone to respect that peace,” a statement read at the time.
At the height of her child stardom, Church performed for the likes of Nelson Mandela, Britain’s Queen Elizabeth II and Pope John Paul II.