First,

There are four common fakes of the 1943 bronze cent:

Copper plated steel cents. These will stick to a magnet.

Altered date 1942, 1945, or 1948 cents. Every "4" in 1940-49 cents is different, and the date of a 1940s cent can be determined entirely by looking at the third digit of the date.

Cast counterfeit 1943 bronze cent. A
specific gravity testcan determine whether the specific gravity matches a genuine 1909-1942 bronze cent or matches a genuine 1944-1956 brass cent. As an alternative, most jewelry stores and local coin shops can use an XRF scanner to determine metal composition. (XRF is non-destructive testing.)

Die struck counterfeit 1943 bronze cent. These usually will pass the specific gravity test. Die struck counterfeits usually are made from transfer dies or spark erosion methods, and lack the detail generally found on genuine coins.
Please post the weight of your coin. That is the first step in deciding the next steps. Clearer photos of the obverse and reverse would also help.