What's That Noise?

Hey guys,

About three months ago another driver blew through a stop sign in a residential street and I had to slam on my brake hard to avoid a collision. Since then, I would hear this high pitch clunks that comes on when my foot touches the brake pedal. The weird thing is that it only comes on randomly and the first few minutes of me driving my truck. I could not isolate where that noise came from because it does not come on every time I put my foot on the brake pedal. What's the problem and is that something I should be concern about? Thanks for any info/suggestions.

Kevin

 

Brake pad clunk?