I'm so sorry you're going through this. It sounds like your husband is going through a midlife crisis and may be feeling like he's not getting enough attention. No, I am not defending what he's doing. No matter how he feels he made vows to you and the two of you have 4 children and 1 on the way. He might be feeling overwhelmed but what about how you feel? Having 4 children, one on the way, taking care of them, him and a home is so much work. Does the other woman know he's married and has 4 children with you being pregnant? If not, I think she should know. I can't understand why any woman would want to be with a married man. Almost mo married man leaves his wife for another woman. Have you talked to him about couples counseling? I think this would be a good idea. I'm here to help any way I can.