Confirm a couple times that your scale is reading accurately. If it is, then yes you almost certainly do have something good, either a very overweight copper plated zinc cent, or a 1984 D cent struck on a 95% copper 5% zinc planchet. If the scale is accurate I would do a specific gravity test on the coin. If it comes back around 7.17 you have a Zincoln, if it comes back around 8.92 then it is struck on copper and the next step would be to get it slabbed. I rarely recommend slabbing, but no one is going to believe what it is without it in this case.