Your best bet is to assume it's not original. That will save you a lot of frustration down the road (because everyone re-creates things that have been in print for ages).
You can also record a video of it and put it on YouTube as Unlisted, or Vimeo behind a password, and have some people who know what they are talking about look at it. Folks like RealityOne on these forums. You can also do independent research on sites like this: http://archive.denisbehr.de/tree http://www.conjuringarchive.com/
It's a good idea to do extensive reading before thinking something is original. I can't tell you how many times someone has told me they created something original that is exactly the same as stuff in Expert at the Card Table.
I assume you are talking abt a cardistry move and not a sleight?
In which case, you should upload a video on You Tube.
Many, MANY cardists have often uploaded a small video on YT before making a tutorial or even showing the audience the full move or flourish.
Get in touch with some cardists thru Insta and stuff and find out from them if they think the move is original.
BUT upload a video of it first. Why? Well, as far as I know, the cardistry community is pretty friendly and honest, but there are a few rotten apples in every basket...altho sometimes they fail to spread their rottenness, but anyways...better be safe than sorry.
Don't worry. A video of that move does not need to be a brilliant example of cinematic brilliance. Just film it with a good quality camera and add some music to it. THEN ask cardists for their opinion. And maybe, even in the comments section of You Tube, people will point out if the move is original or not. You can take down the video later if you feel it really IS that bad and you wanna upload a better one, or none at all.
As said before, most probably (not definitely) your move is a DERIVATION of some other move. It will take a lot of coincidence for your move to be EXACTLY something that someone else created. Maybe your move consists of smaller moves made by others...doesn't matter. New combos are appreciated as much as new moves are. The good news is that since cardistry is a relatively modern platform, it will be easier for you to check if the move is original than it would have been for a magician to check if his sleight was original. Good Luck!
A small piece of advice...you should really go the extra step I mentioned and contact cardists and upload your video publicly (as I said, take it down after you have got your answer, if you wish). You don't wanna be one who invents a fantastic move, keeps quite about it, and a few years later, sees an established cardist get credit for the move he invented first.
Anyways, if you become friends with cardists in the process, all the more better!