The 31-year-old, who married her husband Nick Lachey last July, announced last month that she is expecting her first child.
"I have no complaints - it's been fun," Lachey told Us Weekly. "It's been a fun process. Every day is a new adventure!"
Lachey revealed that she and her husband are "beyond-the-moon excited" about becoming parents and explained that they have been "yelling" baby names around the house to test them out.
She added that she is focusing on staying healthy, saying: "[I'm] just trying to eat constantly and be aware of what I'm putting in my body and to maintain my calorie intake.
"The only gift I can give my baby right now is what I put in my mouth and how I am health-conscious about trying to stay active... I'm not going to throw caution to the wind. [My baby] is actually developing and growing. I think about everything I eat and drink."
Lachey has previously admitted that she always imagined having a boy first, but explained that she would also love a girl.
> Nick Lachey: 'I will be Vanessa Lachey's birth coach'