My guess is that you're referring to the listing as it appears on the different sites on the internet, maybe Trulia specifically? Your listing was most likely syndicated from the local MLS out to sites on the internet, including Trulia. Unfortunately, when a house is sold and listed as sold in the MLS, it often doesn't get updated via syndication until later. Sometimes this is a manual process, sometimes automatic, it depends on the office.
One thing you can do is call the listing brokerage and request that they update their syndication to sold so that the home comes off of Trulia and other similar sites.
I just checked MLS, and the listing agent changed the status of the house you bought to "sold" on Feb 15th, the day after closing. This seems reasonable. Most of us wait until the day after the closing to change the status on MLS because not only does it have to "close" but it has to get recorded at the registry - which can take many more hours to accomplish, so we wait to make sure that happens.
Good luck and congrat's on your new home!