You need to determine exactly what type of document you signed. NYS requires an agency disclosure form for both buyer and seller. It is a simple form. It is not a contract. Some real estate companys also use an Exclusive Buyer Agency form. It is a legal contract similar to what a seller would sign when listing their home. These contracts generally have a finite time and a specific location (county) and spell out your obligations to one another. Read the form carefully. If you still have uncertainties, show the form to your new realtor.
Here is a link to the form: http://www.dos.state.ny.us/lcns/realestate/1736.htm