Why is he wanting to come back?
is it just for the physical atributes & what he can get.
What are your ages?
Does a religious attitude take any part in your relationship? (just so i don't offend)
Why was he angry & hostile towards you? If He is annoyed because you fell pregnant then he needs to remember his responsibilities.
Relationships fail for many reasons. There are five things that will virtually gaurantee a relationship, they are: Conversion togeather,(religious)
Commitment
Compassion
Compromise
& most of all Communication
If there is a break down in any of these it will reduce the success rate each by 20% although communication should account for a double helping.
If you are serious about your relationship search for Mark Gungor's "laugh your way to a better marriage" so long as both of you are prepared to commit then it would be a good place to start. My wife & i broke up 15months ago & it was only these 5 principles that allowed us to sort through our stipidity & selfishness & now we are more in love than we were ever before.
You have responsibilities towards your son & so does your ex.You both need to put your son's needs first!