my first class mail("regular" mail) get to china in 10 days,
go to www.USPS.com to check your track number to see the status. you might only see your mail left US. the problem is In China. The contract for USPS in China is China Post. you may have trouble to trace your mail in China though them.
on the other hand, other express services like FedEx are traced all the way.
you may get your postage or part of the postage refund back to you. but for damages, only Insured mail can get money for lost/damaged.