Funny Break sound

[AlbuquerqueM45sport]

After getting the car warmed up, getting the breaks up to normal operating temperature, then letting the car cool down on a cool day I get back in the car and when I use the breaks for the first couple of times I get a metallic sound. Similar to when a car needs a break job. Sounds like metal to metal. After a few stops everything sounds normal. The breaks were done by the dealer less than 5,000 miles ago, any thoughts? Stops normal, just sounds like crap!