The 'My Life Would Suck Without You' star is expecting a little brother or sister for daughter River Rose, but unlike her first pregnancy, she has been plagued by all-day sickness this time around.
Speaking on CBS' This Morning in the States, she explained: "I'm familiar with all-day sickness. I have to get IVs and fluids because I get so dehydrated. It's really bad."
Kelly, 33, announced her pregnancy on stage during a concert in Los Angeles in August. She didn't even tell husband Brandon Blackstock she would be making the news public!
"I couldn't get through it and I was crying so hard and I thought, 'These people are going to think I'm on drugs but I'm about to lose it like a crazy person.' I was like, 'oh I gotta explain.' And then it just came out," she said.
Kelly also spoke about her critics, saying taking a dig at her from behind the computer is a "cheap shot" and she doesn't let it bother her anymore.