Is this a rolling contract?

Hi All,
I'm looking to sell my property, I currently have tenants in there at the moment, a new fixed term was agreed but the tenancy was never signed by myself or the tenants (this was back in Nov 2011). Am I right in ammusing we are now on a rolling contract? I'm aware that if there are any viewings etc I'd have to give 24 hours notice but I'd like clairty on the tenancy agreement before I say anything to the tenants!

Thanks in advance
Crippy