Well, he's probably a bit shocked. There is a very big difference between 'I think I'm pregnant' and 'I am pregnant'. He may need some time... and while you may really need his support right now, he may not be completely capable of providing it.
On the other hand, he may truly want nothign to do with it, as he's uninterested in the child... in which case, there's not much you can do :(