clutch question

I just got a new clutch put in a few weeks ago, drove about 400 miles since then. The mechanic told me to take it easy for about 1k and I have been. I just noticed this on my way home from work if I let off the gas it sounds like my brakes are shot but I don't brake and I'm not shifting down into high rpms either. when I brake I do hear it but I'm clueless

 

Do you smell anything?
From my understanding, it could be a few things

 

it kinda smelled like a clutch burning or metal burning. The smell was comming from the back and after driving past people and letting them listen we were thinking the clutch isn't the problem. I may have teeth missing in/and my rear diff is going out? Not sure what you were thinking but the noise is comming from the back and when I put it in reverse you can hear it when I accelerate

 

Rocks stuck in the calipers can sound like a brake pad squealer,,but usually just backing up removes them.

 

Thanks guys but apparently my one back mudflap was flush with my tire so all. Had to do was put the bracket back and the noise stopped lol