Doubt about having child with a man who already has children..?

My boyfriend is 12 years older than I am. He has four children ages 1 to 15. I am only 23 years old, so I'm not wanting to pop a baby out anytime soon... but I have been wondering what it will be like if I did have a child with him. He has already been through four pregnancys and he has seen all of them delivered. I feel as if it won't be as exciting the fifth time around. I feel as if it'd be better if I had my first child with someone who hasn't been there done that. Does this make any sense?