We're only 9 days into the month and the POs were closed on the First, the Third and the Fourth.
So you are worrying after only six days in transit.
In my experience, most items take 20 days (or less) to arrive from the USA.
If it hasn't arrived by Day 20 after purchase, ask the seller for the date of shipping and the service used. Any response is acceptable.
If it hasn't arrived by Day 30, open an Item Not Received Dispute in the Resolution Centre
But it will arrive well before then.