That's how I would start my joke if I had one.
How about this?
A lady walks into the dr's office. Doc gives her a dosage of Prednisone. Says it will make her bloated. Two days later, the lady's daughter looks at her and says, "Mommy? Is there a baby in your belly?" The lady, breathing through her teeth trying desperately to not strangle what was once her pride and joy replies, "No. Trust me. There is no baby in my belly." To which the precocious child asks while lifting up the lady's shirt for a peek, "Are you sure? Because your belly is getting puffy." Lady's husband is standing in the kitchen holding his stomach he's laughing so hard that he's choking on his giggles.