Did USPS lose my package? or was it possibly stolen from my mailbox?

So 2 days ago (June 27th 2011) I sold an item on Ebay and I put it in my mailbox at around 1:00PM. The mail man usually arrives at my house at around 4:00PM. I have a tracking number and everything but when I check the tracking number, all it says is: Electronic Shipping Info Received, Jun-27-11, 00:00 AM. This basically just means that I printed the shipping label...Is it possible that my item was stolen from my mailbox? and if so, what should I do?