I would not start worrying just yet! USPS is different than ups and fedex as in if it goes to the wrong hub your package will be delayed a day and UPS and Fedex will go out of their way to make sure you receive your order on guaranteed delivery date if at all possible! ( They will have another driver bring it, have another driver bring it to your route driver during their deliveries, or have your driver pick it up if they are close enough to that Hub).
I have noticed over the years with USPS if it is not at my local hub by 7:30-8:00am then it is probably not going to be delivered that day. It was probably just a mistake and went in the wrong bin and will probably be sent to your local hub tonight to go out for delivery tomorrow!
However you did say it was shipped domestically but shows up as international package which is weird unless it was a remailer situation! I will give you this piece of advice though, on a controlled delivery they must have your signature to be able to do anything or to have anything on you (proof that you did order it if you sign for it) so if they want a signature on the order DO NOT sign for it and act like you know don't anything about the order and you will be fine..
I also agree with
@Heavenlee to use a 3rd party app to track it as well because a lot of the times they are updated more often than than the USPS info.
If your package does not leave that hub by tomorrow or does not go out for delivery make another post here and I will try to help you out and give you a few other tips you can use.
I hope everything works out and have a great night!!!
BIG DREW