Okay, I know a bit about Estate Agency, I've never been one, but I worked for one of the biggest ones in the Senior Management side of things at Head Office.
It is a terrible time of year to go on the market in terms of getting viewers - only really serious buyers will be out looking for a new house this close to Christmas. The average house sale is a 13 week type affair from listing to exchange so you have Christmas bang in the middle of that where literally nothing happens. So its people who have been gazumped and have their chain in place who are currently looking for a house seriously, and not much else. The vast majority of people who are thinking of putting their house on the market to then look for one to buy will do so after the new year, sometime in late January and then in the Spring. Things always pick up in the spring. If your house is an "ideal first time buyer" house then this is slightly less of an issue - but if its something that would be somewhere in the middle of a chain then its possible nothing much would happen regardless of price, unless its an absolute steal and you don't necessarily want to be selling for a steal.
That said, your Estate Agent should have a list of "hot buyers", which are people looking for your exact type of property and location in a position to proceed. It might be that they don't have any, due to the time of year, due to being shit at marketing, or due to your house being less popular in terms of location/size etc. If they have done as they should and alerted your their hot buyers and have not had any interest, they should have at least communicated this fact to you.
One thing you can do is get your local friend to either ring them or drop in to the branch, saying that they are looking for a house that vaguely matches the description of your house (in terms of size/area and price, give or take a little). If the Estate Agent does not give them the property particulars of your house, they are not doing their job. It can be tricky to ask a friend to do this, as a good Estate Agent will want to take their details (name, address, email address etc) and probably start asking slightly awkward questions about whether they are on the market yet and that can be uncomfortable for some people so you might want to choose a more outgoing friend who is good at bullshitting if you do that. Its a bit of a pain but it would give you a clear idea of whether they are being proactive in marketing your property.
Good luck - things will pick up in the Spring, trust me.