Hannah - who plays new girl Tonya Dyke in the ITV1 comedy - revealed her exciting news this morning, adding that it has come as a wonderful surprise because she was suffering with fertility problems.
During an appearance on Lorraine, Hannah said: "I am [pregnant], which will be a bit of a shock to some of my friends who I've not managed to call yet… I'm pregnant!
She added: "I don't mind saying it, I know plenty of women go through it, but they kept telling me that my fertility was so low and that it might not happen.
"I just feel massively privileged and blessed. It just feels more important than any other job I've ever had. It's incredible how it hits you suddenly. It's taken my breath away, I'm so pleased."
Hannah, who made her Benidorm debut this year, had kept her pregnancy a secret as she had been feeling poorly. Thankfully, the early symptoms have passed.
"I'm fine now," she said. "I wasn't great, which is why I wasn't telling anybody… just rough - that leg thing where you want to screw them off and chuck them away. But no, all good now."
Hannah is continuing to work throughout her pregnancy and is getting ready to shoot a film in March. She is also helping to arrange a West End concert with Gok Wan for the Philippines flood appeal.
The Kiss Me Kate star is due to give birth on 20 July. Congratulations!
More celebrities who have announced their baby news in 2014: