USPS did scan your package, otherwise you'd only see "shipping info received" on the status update, not "on its way to the sorting center" which happens after the package has left (and been scanned at) its origin post office. As DTR pointed out, Chicago is probably the final destination where these international packages arrive before being sent outside the country. Also, unless you paid for expedited service, your package was probably sent via truck from its origin post office/box to Chicago -- which itself could take a number of days. The whole "airmail" thing simply means that it gets taken via a jet across the Atlantic, not that it is fast like domestic airmail would be considered.
Remember that this country is huge, and your entire country would be more like a small state here. Despite that, the post service is very fast for domestic delivery, especially the Priority Mail service which often arrives faster than comparable services like UPS or FedEx. International packages are just a different matter because they take longer in general anyway, and unless you've paid extra for expedited service -- which you did not, because Priority Mail International is not an expedited service -- there's no real expectation that it will, or should be delivered quickly. Therefore, it's not imperative to provide to-the-day tracking details on some package that will take 1-2 weeks to arrive anyway.