I know what you mean! I was thinking the same thing. I think it is because of 2 reasons:
1) someone has already answered your question, so everyone would just tell you the same thing
2) people don't know the answer so they don't respond, but with BFP's all you have to say is the same old congrats and HH9M.
Don't feel bad, I'm sure a lot girls just don't know how to answer the question posts!