The Eureka actress and husband Raffaele Fiore will welcome the baby at the end of May.
"I am so thrilled I am going to be a mother. I fall in love a little more each time my baby moves," Cerra told People.
Cerra went on to say that while she has a few problems which can sometimes complicate pregnancy, she has so far enjoyed the experience.
"So far pregnancy has been a breeze. Sciatica can be difficult, otherwise I have been very fortunate," she explained. "Ultrasounds are probably my favourite - being able to see my little one. It's all an amazing experience."
Cerra and Fiore have dated since high school and married in November 2010.
Eureka was cancelled by SyFy in August 2011 but was given a bonus finale episode to wrap up the show's storylines.