I thought about that too. If I ever lost a child, part of me feels like I really would want another, but at the same time... Would I be having one just to replace the one that is missing? To try to fill in some hole I have in my heart? I don't know for sure, but I had to have faith in the fact that we both feel like our family is complete. I didn't want to make a decision based out of fear. Vasectomies can be reversed, and adoption or fostering is also always an option.
In the end you'll have to decide based on what you think is best for you. If thats a real fear you have, and you would want to have another child (or think you might change your mind 5-10 years down the road), then a different form of BC is probably a better option.