If you don't find any coolant in the oil or vice versa and you're not losing coolant and all cylinders are firing...well, there's a real good chance you're gonna be ok.
The oil change and test for metal particles is a good idea, but finding a few particles my or may not be an indication of a problem. Now a WHOLE BUNCH of metal is a completely different story. But I'd think that would be accompanied by some other symptoms like lotsa steam out the exhaust, knocking or other bad noises. If ya don't got none o' these, then yer prolly ok.
