Hi Benito,
The scheduled report should finish at the time you have set it to ideally.
If you are getting any scheduled report that you dont want anymore, just go to Components> Scheduled Reports and click on the red cross in the Manage column against the report name to delete that report. Also you could go into the 'edit scheduled report' and specify the number of occurrences or the date you want the report to end.
I hope this helps.
Tanmay