I have noticed that randomly (not every time I break) when I press on the brake pedal, I hear a grinding noise that seems to go around with the tire. This isn't a constant noise, meaning it pulses like it is going around with the rotor. I had my break pads and rotors replaced within the last 6 months and it just started making this noise occasionally when I am braking. There doesn't seem to be any consistency of when it happens, but it will make the noise randomly for a little while every time I brake, and then suddenly it is fine for many miles with no sound, until it comes back again.

Does anyone have any ideas what may be going on here? Thanks!