You can pull of your oil filter, cut it open and see if there are any metal shavings in the element. If there isn't anything in there, that's good. I would then open the hood, start the motor and try to figure out where the noise is coming from.
If there is some crap in the filter, then you will need to pull the motor and yank the crankshaft out and check all the bearings. There is no way around it, and the sooner you do it, the better off your motor is going to be.