May not be the problem for you, but I threw a pad last year, and it went down similarly to what you describe. No pull, just some grinding when I applied brakes. I let it go for a couple days while I was on a trip. Figured it was dust, sand or mud as I was out in it, a long way from a garage.
Unfortunately, I didn't realize what was happening, and when the pad came off.....no brakes! Going downhill I might add.