All of your Nectar points are in your Nectar account sign in to see them https://www.nectar.com/homepage
If you previously coverted any points into eBay vouchers they are valid for 12 months from issue and are shown at checkout way down on the left side.
If you don't collect or spend any points for a year, Nectar assume you no longer want to take part in the Nectar programme and close your account.