The Baby He Wanted (Brothers, Strangers)

It's a dream come true…if only she'll say yes 

He doesn't believe in love, but Detective Bran Murphy does want a wife and family, which seem unattainable when his fiancée breaks it off. Drowning his sorrows the night before what was supposed to be the big day, he finds comfort in Lina Jurick, a woman with a sad story of her own. And then, inexplicably, she disappears without a word the next morning. 

It's a good half a year before Bran runs into Lina again, during a murder investigation. Lina is the key witness. In fact, she's the only witness, and she becomes the killer's next target. 

She's also six months pregnant.