Jenny Harris always expected that she’d fall in love, get married, and have a baby–in that order. Now, very pregnant and not quite married, she actually doesn’t mind that she and her live-in fiancé, Dean, accidentally started their family a little earlier than planned; she’s happy to have so much to look forward to. But Dean–whom Jenny loves enough to overlook his bad facial hair, his smoking habit, and his total commitment to a cheesy cover band–is acting distant, and not in a pre-wedding-jitters kind of way. The night he runs out for cigarettes and just doesn’t come back, he demotes himself from future husband to sperm donor.

And the very next day, Jenny goes into labor.

In the months that follow, Jenny plunges into a life she never anticipated: single motherhood. At least with the sleep deprivation, sore boobs, and fits of crying (both hers and the baby’s), there’s not much time to dwell on her broken heart. And things start looking up. She learns how to do everything one-handed, makes friends in a mommy group, and even manages to give dating tips to her sweet, clueless father–who’s trying to court her sassy mother again, fifteen years after their divorce. She also gets to know a handsome, helpful neighbor–with a knack for soothing babies–who invites her out dancing. But Dean is never far from Jenny’s thoughts or, it turns out, her doorstep, and in the end Jenny must choose between the old life she thought she wanted and the new life she’s been lucky to find.