Is my usps shipment lost?

I bought a thing off ebay. Paid on the 12th, and the seller ships on the 15th. Well, not so bad, I guess. Anyways, the real problem is that when I use my delivery confirmation number, it says it had left their Cincinnati, OH facility on the 17th, and it says expected delivery is the 18th. It is first class mail. Well its already the 20th (today) and it still says the same thing! No updates, does it make no stops anywhere else? Is it strictly from OH to NM (I am in albuquerque NM). Something else that worries me is that the shipment was originally from Illinois or Indiana? (State with the abbreviation IN). So its one of those two, why the heck it go to OHio for? Anyways, im Just big worried, should I wait more? I ordered things through 1st class mail from NY and they arrived in like 3 days! So is it lost or it just takes long? Thank you.