BOOK-A-HOLICS discussion

A year or so ago I read a book about a girl who was either a detective of some sort or a private investigator and there's an awful lot of fighting in it and the guy they're protecting or searching for is the father to the baby she's having and it turns out she was scientifically impregnated and it wasnt them having sex.
I know that seems useless but that's all I can remember.
The title had either devil or evil in it.