Help!!!

Here's the deal. I have a very light metal sqeaking sound coming from the front right of my car. I can only here it when I am rolling about 3-8 mph. Any faster or slower and I cant hear it. Another weird thing is, sometimes it does it and sometimes it doesn't. Any opinions on this? All help is much appreciated.

It's a small rock in the front rotor. try going forward, then reverse, then forward, reverse, etc. to try and dislodge it... if not it'll come out from normal driving.