Don't worry about it. USPS usually only scans packages at point of acceptance and delivery so there are often significant gaps like this. Especially with international packages where there can be holdups with customs and the like. I'd give it the same amount of time as you would normally expect for a package shipping to you from that address, then at least a few more days before taking the time to check with your PO.
Even though their tracking is terrible, I've had an internet business for almost a decade shipping through the USPS, and they actually do a great job with getting packages to their final destination - even overseas where we ship about 20% of our packages.
Remember, the seller has absolutely no control after they carefully pack and address a package and drop it off at the post office. For international packages, the delay is almost 100% of the time customs. Try your best to be patient and give the seller the benefit of the doubt until you have a real reason to think that any delay was their fault. It sounds like they did deliver it to the post office promptly. Hopefully your package will be arriving safely any day now.
Even though their tracking is terrible, I've had an internet business for almost a decade shipping through the USPS, and they actually do a great job with getting packages to their final destination - even overseas where we ship about 20% of our packages.
Remember, the seller has absolutely no control after they carefully pack and address a package and drop it off at the post office. For international packages, the delay is almost 100% of the time customs. Try your best to be patient and give the seller the benefit of the doubt until you have a real reason to think that any delay was their fault. It sounds like they did deliver it to the post office promptly. Hopefully your package will be arriving safely any day now.