It was just supposed to be a routine checkup! Jo Dee Messina says she wasn't ready for her new baby boy to be delivered on Wednesday, but while she was getting checked out, the doctor told the singer she needed to check in at the hospital. Not long after, she was a mother to her second child.

Messina has documented her pregnancy at the humorous and insightful Fumbling Mom Blog. In an earlier post she wondered if the baby had "dropped," but didn't seem too concerned about it. That same day, her trainer had her doing 45-pound squats!

"I had gone to my Drs directly following a photo shoot," Messina writes in Thursday night's post. "Full make up. Tall boots. The works. I was so not planning on having a baby that afternoon. I didn’t have my bag packed. No camera, except for the one one my phone. Nothing in preparation for having a baby."

Her husband, Chris (pictured above with their children) arrived, and within 20 minutes he was holding 6-pound, 13-ounce Jonah Christopher. It's the second son for the happy couple, who welcomed Noah in 2009.

"Both boys look like their Dad. To adore someone so much, as I do my husband, and then to have your children look like him, I can’t imagine a more beautiful thing," Messina gushes.