The model and actress, who is expecting her first child with boyfriend Thom Evans, confessed to being left bedridden by horrific bouts of morning sickness after first discovering the news.
The Piranha 3D star, who is now almost five months pregnant, told the News of the World: "I was badly sick in the beginning of the pregnancy. For the first two months it was horrible.
"I couldn't get out of bed and I was sleeping all the time. But I feel much better now and I'm still going out and having lots of fun."
When asked if she found any other aspects of impending motherhood particularly challenging, Brook admitted: "I miss not being able to have a drink."
Brook's mother Sandra Parsons recently claimed that the 31-year-old is "unbelievably happy" to be pregnant.
Brook's rugby player ex-boyfriend Danny Cipriani has also stated that she will make a "great mum".