So, the idea for this Jam to encourage people to create something new during the month of January. It's ok for people to get started early, but it sounds like you did almost all the work before the jam started and would have been doing that regardless of this jam's existence.
If that's the case, it's not entirely in the spirit of the jam, but I'm not here to police what does it does not belong in the jam.
It looks like it's available to the other jam participants for free (point 3 on the jam list), so that just leaves point 2: "Support and encourage your fellow JAMuary participants (advice and feedback should be constructive and considerate)."
So, I'll leave this up to you. Are you looking for advice and feedback on your project? Are you down to support and encourage the other jam participants?
If the answer to those questions is "yes," then I don't see anything wrong with your project being included in this Jam!