The Switch (2010)

Meet Kassie, an intelligent and joyous woman flying solo in the world of dating. Despite the hesitations of her worrisome sidekick Wally, she resolves that the time has come to embark on the journey of motherhood - even if she must do so without a partner, relying on the assistance of a delightful sperm donor. Little does she know, a spontaneous turn of events occurs, leading to an unexpected twist in her well-laid plans. The revelation of this unforeseen change only surfaces seven years down the road, when Wally finds himself in the company of Kassie's endearing, albeit slightly anxious, son.