If you do not have a signed commission agreement with this agent, then, no,
However - they do get to keep the entire commission.
Here's how it works: Listing agent contracts with seller; "You pay my brokerage if we find you a buyer. If the buyer comes from another agent, we'll share the commission with that, otherwise, it's ours."
If only you could find houses on your own, Shade47. We, as an industry, have spent hundreds of millions of dollars to make the information so available that you can access it from your boss's computer, from your smartphone . . . we even put signs up in front of the house and set arrows on the corners pointing to it! You didn't find it "on your own," the listing agent figured out a way to get the information in front of you, and they are contractually entitled to not share the commission.