The former Girls Aloud star, who gave birth to Bobby on September 4, admitted that she'd expected to find breastfeeding 'the easiest thing in the world,' but it didn't come naturally to either her or Bobby.
"I've always thought breastfeeding would be the easiest thing in the world. It's only when you speak to other people who tell you they also found it painful and hard that you realise it's not just you," Kimberley, 32, wrote in her first OK! magazine column since becoming a mum.
"You imagine it will be the most natural thing in the world, but more often than not it doesn't come naturally to either you or the baby!
"It can be quite distressing when it's not working, but we've definitely cracked it now and it continually gets easier."
"Bobby's putting on a good amount of weight each week now so we're on the right track which is a real relief."
Kimberley also recently revealed that Bobby's birth wasn't as straight forward as she'd hoped.
"He'd been in the right position for the last three months but he turned after my waters broke," she said. "The obstetrician tried to turn him but he kept flipping back so she made the call to assist with forceps. I'm grateful we got him out with forceps."
Bobby is Kimberley's first child with long-term partner Justin Scott. The couple have been together for over 10 years, since the beginning of Kimberley's days in Girls Aloud.
She is the second member of the band to become a mum. Nadine Coyle welcomed a daughter, Anaiya, in February.
More on Parentdish