Call the clerk on the 14th to see if the dismissal is on file. If it is, you do not have to go to court. Otherwise you should go, request for dismissal in hand, and ask if he had submitted it to the court.
It sounds like your brother has dismissed the case against you. The "without prejudice" part means that he has the option to re-file it again at a later date as long as it is within the statute of limitations. I agree with the previous response that you should call the court clerk (even now) to see i the dismissal has been filed with the court and confirm with them the case is dismissed. If you can't get that confirmation, show up at the court. Good luck.
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