During Hajj, when I came to throwing the pebbles, I doubted the number of pebbles which I had thrown in the pit. So, I considered the lesser number in order to be sure that they are seven. When I threw the pebbles of the next Jamrah and counted the total number of pebbles, I discovered that eight pebbles were thrown at the first Jamrah, because I had a certain number of pebbles with me. Am I required to do anything?

All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

Since you considered the lesser number when you doubted the number of pebbles you threw at the Jamrah, you have indeed done what you were required to do. If you later discovered that you had thrown eight pebbles, this is not harmful because you have fulfilled what you are required to do.