clunking brakes?

[tastyratz]

ok so ive been driving on the highway and noticed steering wheel shake alot. its very intermittent cuz sometimes i brake and its fine but sometimes my wheel moves up to an inch and its kinda scary like a wheels gonna fall off or something. the thing ive really been noticing however is when i engage the brakes (you can hear it more going slower) my car makes a loud clunking sound from the front end. like im not talking low im talking loud and it sounds like something is really smacking hard, almost like im taking a lead p ipe and hitting my brakes with it. it also makes the same sound when i disengage the breaks however. if i engage and disengage but move my foot faster it gets louder. the car was pulling slightly to the left earlier but its not now and if i slam on the brakes it stays straight all the way to stop and brakes fine. id had a feeling that maybe one of my brake pads feel off but i dunno it dont really seem to make sense, if a pad fell off id hear grinding against the rotor and have a significant pull. the sound scares me enough to not drive my car however and im gonna take apart my brakes today but i wanted to know if you guys had any ideas...