Unexpected Love by Fiona Davenport

Tech billionaire Jonah Carrington had no plans to have a family. Then he suddenly became the guardian of his one-month old nephew, and his heart was filled in a way he hadn’t known was possible. He was prepared to be a single father until he unexpectedly fell head over heels for his young, innocent neighbor.
He had to wait four long months to make her his, but when the time came, he wouldn’t hesitate to put a ring on her finger and a baby in her belly. Their love may have been unexpected, but Jonah knew it would last forever.