The Crash Book by Freida McFadden

The Crash by Freida McFadden is a thriller about Tegan, a pregnant woman who crashes her car in a blizzard and is rescued by a seemingly kind couple, Hank and Polly Thompson, only to discover she is a captive in their isolated cabin as Polly, a former nurse, has a desperate plan to keep the baby for herself. Tegan must escape their clutches and protect herself and her unborn child from the couple's twisted motives.