Don't panic!
The postal system is very efficient at keeping track of the shipments they handle.
If you are not home when the carrier arrives, you will get a Notice telling you where and when it can be picked up.
If the shipment is valued over $20CDN (~$16USD) you will be charged applicable duty, Sales Taxes, and a service fee of $9.95 before Canada Post will turn it over to you.
Even if there were a delivery problem, you are covered by eBay and Paypal's Buyer Protection programmes.
