Canada Post may have accidentally delivered your package to the wrong address. Postal workers may occasionally drop packages at your neighbours’ homes or wrong mailbox. Ask your neighbours if they saw it or simply look around their premises. You may also check the community mailbox. 
Postal workers may also have scanned a package as “successfully delivered” but it will actually arrive the next business day. Please allow one extra business day to see if you package arrives. 

If you do not receive it 2 days after your expected date, let us know so we can file a trace with the post office. Once a trace is filed, Canada Post will conduct an investigation (which can take 5 business days to complete). If they can locate the package, they will ship it to you and you’ll get it a few days later.

From Canada Post

“The investigation involves contacting the addressee to confirm delivery, or to better understand how they receive their mail and, as applicable, if they checked: with the front desk, security or mail room at the receiving address to see if someone else accepted the item on their behalf; their Community Mail Box for the item or parcel compartment key; around their property to see if the item was left in a safe location or in a mailbox attached to their home. In rare cases, a delivery scan is entered into our system before the item is delivered. If you become aware that the addressee has received the item before we contact you, simply reply to this e-mail indicating the item has been received.”