Pregnant wife hates me right now!?

My wife and i have been married almost eight years. We have 3 girls ages of 8, 3, and 18 months. She is now pregnant with the fourth approx. 14 weeks now. She absolutely hates me right now. It has got so bad she is staying with her mother. I am very understanding about the pregnancy and i am going out of my way to do all of the housework and take care of the kids. I have been laid off for almost 1 year now, and she is the only one working. She is an RN and is changing next week fron nights to days and is going down to 3 days a week. I am in school and i have been discussing with her going to find a job. She is not open to any discussion and i try to explain to her that it is probably hormones. She says no its just the way she feels. None of the other pregnancies,hoping it means this one is a boy, have went like this. I dont know what to do or think im very upset and i need my loving wife back. Im 28 years old and she is only 25. She has never acted this way before, and im hoping its the pregnancy. Any advice or knowledge would sure help. Thanks ahead for replies.