To be honest you need to think about you. You gave him a chance and unfortunately he threw it back in your face. If I was you I wouldn’t let him be at the birth because you are not in a relationship with him and its your birth not his, he decided to walk away. He just can’t call all the shots when he feels like it. He is showing no respect for you, and he needs to learn your not someone who can be used time and time again.
In terms of contact when the child is born, he is the father and does have a right to see his child. However, remember you are the primary care giver and if you choose to let him see the child, you choose an amount of time you see fit in terms of age, travel etc. Don’t let him call the shots. What he needs to remember is he’s the child’s father, but you are not a family and that you are looking out for the best interests of that child. If there is a reason that the father should not see his child if say for example he may harm the child in any way, then in the best interests of the child I would not let him see the child. However, before making that decision I would seek legal advice.
Hope this helps.