Shipping Time From San Francisco? USPS?

-I recently purchased a pair of shoes from China and they shipped it Express International using EMS. Today at 8:30 AM it cleared customs and was handed over to USPS. How long will it take for USPS to ship my package from San Francisco, CA to Portland, OR. When can I expect my package?When I mail a letter from San Francisco to Portland it usually takes 3 days. The volume of mail in California is tremendous.