I don't know the address of the home but I will answer generally. It could be because the listing agent never went back into the MLS system to mark it SOLD. If that was the case, then sites like Trulia will also not be updated because they draw some of their information from the MLS systems around the country.
I would call your agent and mention that fact to them and ask them to check on the status of the property on the MLS system. If it truly is still marked Pending or Active, than ask them to call the listing agent of the property and have them update the status to SOLD.
I hope this helps a bit.