Fisher recently used Instagram to give fans a peek at date night with his wife, posting a shot of the pair sitting at a table at Etch Restaurant in Nashville.
While it's unclear who was taking the photo, the couple looked adorable as usual, with Underwood's blonde hair up in a bun as the singer and her husband smiled for the camera.
"Date night with my better half!!" Fisher wrote.
The former NHL player previously gushed about his wife after she held a listening party for her upcoming album, Cry Pretty, at the Parthenon in Nashville last week.
"Parthenon release party last night was unreal!" he wrote alongside a shot of Underwood speaking to the assembled crowd. "But not quite as good as the new @carrieunderwood album!! This album is something special!!"
Underwood announced her pregnancy on Aug. 8 with a video shared to social media.
The star was detailing her upcoming Cry Pretty Tour 360 with fans when she noted that the reason for the May 2019 start date is because she is expecting.
"Mike and Isaiah and I are absolutely over the moon and excited to be adding another little fish to our pond," the 35-year-old said.
Underwood and Fisher are also parents to 3-year-old son Isaiah.
"This has just been a dream come true, with album and with baby news and all that stuff, we're so excited and so glad that you guys can share in this with us and be a part of this with us," the singer added.
When Underwood hits the road next year, she'll be doing so as a mom of two, something she admits has her a little nervous.
"It's going to be a different ball game, for sure," she told the Tennessean. "My brain, I'm such a planner. I want to know how it's all going to go. But no matter who you are, you make it happen, you make it work, you get your team behind you."
Isaiah accompanied his mom on her last tour, which was in support of her album Storyteller, but he was nearly a year old at that point. His sibling will be a bit younger, but Underwood shared that she thinks her son will be happy to help out.0comments
"I think he'll be a really good big brother," she said. "I think he'll be helpful."
Photo Credit: Instagram / @carrieunderwood