For some reason in the 'my documents folder' it saves my son's chat logs when he is on msn.

He has a girlfriend,and will be 14 in a month. I don't like him being so serious but he won't listen. She plays him alot, dumps him for others etc. and basically has a hold on him. I'm not blaming this girl or taking responsibility off my son but I am very concerned. I have talked to him about sex, what a good relationship is etc. My son and this girl are always fighting and are involved in a very unhealthy relationship.

I have had my suspicions that they were experimenting and in his latest chats she emailed that she took a pregnacy test. She said she is late and the test was negative but it is early days yet and may be wrong.
I don't know if she is playing head games with him or not, but clearly they have gone all the way.

What do I do now. My son will be really upset with me if he finds out I am reading his personal chat emails but I don't want him to get this girl pregnant. I have tried to talk to her Mom but she is in denial and says they are just friends and that they are not going out. I wanted to meet with her as I thought they were getting too serious but she wants nothing to do with that. She is not being cooperative and doesn't want to meet the Mom of the boy her daughter is spending all of this time with.

Any suggestions as to how to handle this?
Kate