It's beyond certain that the US Army encountered and destroyed several MG 42s on D-Day. The two static infantry divisions defending the coast (the 709th at Utah and the 716th) were mostly equipped with second line or captured equipment, and as such had numerous MG34s and French and Polish machine guns in their inventories, but no MG42s. However, the 352nd Infantry Division, which had reinforced the Omaha Beach sector with its 2nd Battalion, 916th Grenadier Regiment, was more regularly equipped and certainly had at least some MG 42s in play. Heinz Severloh, a 352nd veteran who wrote a rather famous memoir after the war, claimed to have served an MG42 from WN 62 until he ran out ammunition early in the afternoon.

If you mean "did American soldiers capture and use any MG 42s," I can't say, but I strongly suspect not.