Missing iPad does not show up in iTunes under Manage Devices. Does that mean it's been wiped clean?

My iPad is either lost or stolen as of March 2, 2013. I only today remembered about Find my Ipad, but it only was able to find my iPhone (which was in my lap).

I went into my iTunes account under manage devices. There is said that there are two devices associated with my apple id: my iPhone and my Mac desktop. No mention of my iPad, which does in fact have the same Apple id, and which I have connected to the computer and synced with iTunes many times.

Does the fact that it is not showing up as an associated device mean that it has been stolen and wiped clean?