Fortune's Secret Child by Shawna Delacorte

On a sultry midnight eve, Dr Shane Fortune came face-to-face with his past. For his ‘intruder’ was the woman he’d once loved but foolishly let go. Now Cynthia McCree and her son were his reluctant houseguests. Her reasons for being under his roof were no secret. But Shane knew that Cynthia was harboring a secret. One that had to do with her son...who bore an uncanny resemblance to him!