Carrie Underwood admitted her second pregnancy is "harder" than the first.

"It's definitely different than the first time," Underwood told Entertainment Tonight. "When they say every pregnancy is different, it really is. Just different symptoms. I feel like this one is just a little harder on my body for some reason. But it's been really good."

The 35-year-old, who attended 2018 CMT Artists of The Year on Wednesday also said she's struggling to find dresses to wear to events.

"I'm squeezing myself into whatever dresses I can squeeze myself into," she revealed.

Carrie Underwood arrives at the 2018 CMT Artists of the Year show on Oct. 17, 2018, in Nashville, Tenn. (AP)

Underwood, already mom to 3-year-old Isaiah with husband Mike Fisher, said her son has already laid out a rule for his new sibling.

"He says he won't change any poopy diapers though," Underwood said. "I understand, maybe I can change his mind."

The "Cry Pretty" singer announced her pregnancy in August but she said she and Fisher have already picked out a name.

"We have picked out a name, but we're keeping that to ourselves right now," she shared. "We're fixing to move. I haven't bought anything yet, we still have some of the stuff, cribs and stuff from my son, but we'll figure it out. We're about to move so I'll start buying stuff once we're there. It'd be pointless to buy it and then move it."