"I was on bed rest the entire time ... it was rough," she told PEOPLE's Celebrity Baby Blog at the launch of "Nicole" for a Pea in the Pod.
While baby-on-the-way – a boy – seems to be giving the expectant mom little trouble other than the occasional reminder that he is "looking for the exit," Campbell-Martin is prepared for any bumps in the road – including a few bouts of morning sickness – and is taking them all in stride. "I’m enjoying it. I’m 40, and having a baby!" she says.
"Every moment, every nauseous moment, everything that is good and not so good about being pregnant, I’m enjoying."
Expanding the FamilyDespite their initial hope of having many children, Tisha and her husband Duane Martin have opted to focus the last few years solely on their first born, Xen, 8, who had been diagnosed with autism.
"We really wanted to wait as long as possible," she explains. "I don’t want to say [Xen has] grown out of it, but no one knows." His challenges don’t faze Campbell-Martin, who says that she constantly gives thanks for her son. "Every day I celebrate that boy. He’s one of the strongest, most amazing kids."
The couple have already began to encourage a nurturing relationship between the siblings as they prepare Xen for his new role as big brother.
"One of the key things with Xen was making sure he had ownership with what was going on," she says. For the family, that meant referring to baby as belonging to him and consistently reassuring their son that the little one would soon be joining their household. According to the actress, the plan worked – so much so that Xen eagerly awaits the day where he will no longer be the only child.
"He loves my stomach and he talks to the baby. He can’t wait. He says, 'I don’t want to be the only child anymore. I want my baby out of your belly soon.'"
Back to Work – With BabyAs for her role on Rita Rocks, she jokes that the show has been busy in the baby bump department; Costar Nicole Sullivan is due with her second son on Aug. 25, while Campbell-Martin expects her baby Sept. 21.
With two pregnant women on set, there is scrambling to squeeze in the last-minute shooting schedules. "We’re like, 'I’m tired,' " the actress laughs, adding that she plans to return to the show two weeks after baby boy is born.
"I love work. I love sitcoms. It’s more work being at home. And the babies get to come with us. We don’t miss a beat."
Reporting by LISA INGRASSIA