His Secret by Lynne Marshall

Jaynie Winchester has a plan for parenthood, and all is going well until she goes into premature labor. Without family nearby or a husband or boyfriend by her side, she must face the toughest time of her life alone. She’s an RN, she can handle this, right?
Baby Tara is delivered and sent straight to the Mercy, Inc. preemie special care unit. Anxious and worried, Jaynie is not the only one willing her tiny one to survive. Respiratory therapist Terrance Zanderson finds himself getting involved with Jaynie and her baby, even though he never wants to be a father again. Yet he can’t help growing closer to the alluring Jaynie and precious preemie Tara or wanting to be there for them…until he realizes who Tara’s father is.
Must Terrance tear a page from his own advice? “Consider each day a challenge. Dream big, love with all your heart and think positive. Only you can write the story of your life. Make it a great one.”