Technical metal scrapeing noise, can you help?

[Emm]

my lovely Sei has a intermitent noise from the passenger side front when the car is moving.
To me it sounds like a dragging scrapeing metal sound.
It was so loud that i pulled over to have a look but couldnt see anything, i decided to continue driving slowly, the noise continued but as i steadly went faster it disapeared.
Assumed id picked up something metal from the road and it was stuck then dropped off.

BUT
two weeks later the sound returned just as i pulled on the driveway! just sent Louie out to test drive it and nothing :/ its hidden itself again

what should i be looking at/for?
worried about driving it now

 

[fingers99]

You knows yer onions.

But I'd check first for worn pads, then for the disk stoneguard, then for front wheel bearing.

 

[Sei_rory]

probable wheel bearing noise