The actress, who plays schemer Cindy Cunningham on the Channel 4 soap, revealed the news on Five's Live From Studio Five last night after speaking about how her life has changed since she welcomed her first child Mia in 2005.
She told the magazine show: "I've got one on the way as well!"
Waring's current Hollyoaks storyline sees Cindy facing heartbreak and anxiety after her young daughter Holly (Lydia Waters) ran away.
She continued: "That's how I think I've managed to do all the crying [scenes] because I've been so hormonal!
"I'm already at 12 weeks - I've just had my scan so I'm quite happy to say it and I thought I'd take the opportunity while I'm on here. I'm so excited."
The soap star also confirmed that while Mia is keen to have a baby brother, she wants to be surprised by the baby's sex.