I am going for my pre-approval Wed and have a question about starting to look for houses..

We used several. We were up front - and told the agents what houses we already saw with someone else to avoid anyone wasting time. I was always told its to your benefit to have more than one agent for several reasons...for example different RE agencies have exclusives, also we found some agents work harder for you than others (better negotiators). The only time a conflict can arise is when you see a house with one agent,but buy it through another.

My bro saw a house with one agent, 2 months later the price dropped but the agent never told him - so when a different agent called him about it he told her he saw it with someone else. He was fine with letting her get the commission since she was on top of the market changes, but he let her decide how she wanted to handle it. She contacted the other agent and they split the commission.