Terrible and dramatic scraping noise came from my car wheel. 1st amateur diagnosis was grit in the disk. Second (slightly less) amateur diagnosis was a worn break pad. The noise went away after about half a mile, so I'm inclined to go with the grit theory.
If it sounds ok now should I check the breaks, or just not bugger about with them?
Hint: cars, unlike animals, do not heal themselves. Any problem will not get better, only worse and more expensive.
You have a jack right there in your car. Take the wheel off and have a look around. If you don't know what you're looking at, I bet you have a friend who does. Taking the wheel off will certainly not do any harm, and may save you some money. Almost all disc brakes are designed to let you see the pads if you turn the steering so that you can look into the caliper. Replacing brake pads is actually one of the easier jobs a person can do themselves.