Set up a MyChoice account at ups.com. You have many options to monitor shipments, get updates, etc etc.
You can enhance the MyChoice account by paying $20 a year to have UPS keep your packages and deliver them to you. So many companies do the UPS to USPS drop that it's worth the $20 to skip it.
The UPS to USPS drop is the slowest and lowest priority mail for USPS. It's normal to see it sit for days if USPS is busy.
That said, I really don't think you got the faster shipping. The UPS to USPS drop off is usually done with the lowest possible shipping option available at retailers.