I suggest in the post below that you do not query after you've written your first novel; that you wait, write a second, revise, then query.
The question then arises: is this your "first novel?"
When I receive a query letter with the phrase first novel, my assumption is you have not been published. In fact I'm praying this is NOT the actual first novel you've written.
I don't care how many are in the portmanteau in the attic wrapped lovingingly in pink ribbon. I only care if you've been published previously.