1st Question: Is it worn? Most proofs do not go into circulation If not then: Does it have square rims, a brilliant finish, and really sharp details? If so, then yes, it is a a proof Here is an helpful link https://www.coincommunity.com/forum/topic.asp?TOPIC_ID=73968
The coin's front looks must of it great, it has a few scratches, not many, the last "T" in the word "TRUST" WITH A 20x MAGNIFIER IS very weak in other words you can hardly see it, all other letters are very clear, on the back side everything is very clear. The rim is square, not round.
The easiest way to get the correct answer is to post a clear photo of the coin both OBV. and REV. A coin can usually be identified as a proof by the die markers.
That's what I figured. Just based off that, I would say there is a 99% chance you do not have a proof. Not saying it is impossible. Just improbable. Pictures of obverse, reverse, and side of the coin would be helpful.
FYI - Only 32,600 proof 1942s were minted, opposed to 657,796,000 business strike 1942s. The odds of you finding one in your change out of the billions and billions of cents that are circulating are pretty slim.
@Roberto G. Wantland In addition, the 32,600 proof cents were sold to collectors and Collectors aren't going to put them into circulation. Occasionally proof coins do enter circulation, but that number would be extremely low. There is an overwhelming probability that you have one of the 658 MILLION business strikes, and not one of the few dozen (or less) 1942 proofs, that may have inadvertently been spent.