USPS doesn't have the greatest tracking but it usually means that the person you are buying from has created the shipping labels but the mail piece hasn't actually left the warehouse yet.
Depending on how long this notice has been active, say more than 48 hours, it could be that the items have already left the warehouse but USPS hasn't updated yet. Most likely this will update once everything reaches customs in the United States.
It's just part of ordering from China, your always sort of on edge
