According to Jim: Season 7, Episode 17

7 - 17: No Bedrest for the Wicked

Jim anxiously awaits for the moment when Cheryl is off bedrest so she'd take over all the chores, but Dana urges him to let Cheryl rest until she goes into labor. After meeting Cheryl's gynecologist, Jim learns that Cheryl was already allowed to be more active, but she didn't tell him.