I think it all depends on your agent.
Have the two of you discussed why your house hasn't sold?
Has your agent taken beautiful pictures to post on the MLS and other realtor websites(such as this one)?
Are you satisfied with your agent's performance and advice?
Have you taken your agent's advice(especially regarding pricing)?
Is your agent's advice even worth taking?
Has your agent told you want you need to hear in order to sell the house or what you want to hear in order to get and keep the listing?
Ultimately, this is obviously a question only you can answer.
If you are dissatisfied with your agent's performance then by all means, list with another agent.
If you trust you agent, follow their advice regarding pricing and how to present your home and be prepared to do what is necessary to get your house sold.