This can be a very tricky issue. Of course you have the right to be represented by your own agent, however, the listing agent was the "procuring cause" for showing you the home that you are interested in. Therefore, the Buyer Agent that you do find to represent you in the transaction may not be offered any compensation to represent you. Often times, the Seller agent will agree to compensate the Buyer Agent for representing you but they are not legally obligated to do so.
The role of the Buyer Agent has become increasingly important in today's market. Guiding clients through the buying process in a timely manner and negotiating objectively for the buyer are crucial in a successful transaction today. Best of luck in your pursuit and if you need any further information or assistance, don't hesitate!