I ended some items a month or so ago, with no bids, because one I decided to keep it and the other was somehow a duplicate. Neither of those 2 relisted. I can't remember exactly the message I received, but I think it was the generic "your item didn't sell" message. They were both on their first listing with the box ticked to auto relist.

Edited to add: if you want to play it safe and check, log out and check your listings as a guest (on a search page, not in My eBay).