I was like that in my pregnancies also.
My first labour was horrifying, (20hr labour, epi, hemmorage) I was sure he would end up being an only child. :-k
My 2nd pregnancy saw me absolutely terrified the whole way through, only to end up with a 1.5hr labour.. no pain relief at all. He was born with 2 pushes. (My first son, I pushed for 2hrs!)
My following 3 labours only got easier and easier.. yet I still freaked out at the thought of an upcoming labour.
So, it's just a natural process to be frightened.
Goodluck!!