I am a loan officer who has forged documents on some loans.

There are ramifications and it's a federal crime to do what you've done. I represented a bank officer in a federal charge very similar to this except there was a big loss. The bank has an obligation to file a report of your conduct with the FBI, so you should expect to have a special agent come visit you within several months. Don't talk to the agent, and hire a lawyer. If it were me, I'd hire a lawyer now and send him to the US Attorney's office to try to work out the best deal possible. The likelihood of a charge is high in your case. Find a former federal prosecutor to help you.

Have a lawyer lined up if something does come down and do not talk to anyone except the lawyer and definitely make no statements to law enforcement. Since there was no monetary loss however, it is possible they may decide the case is not worth the effort to prosecute.