The inquirer experienced extreme knee pain during tawaf al-ifada (the coming forth circumambulation) which he was performing on the second floor of the Masjid. He made the tawaf in a wheelchair pushed by a small boy. Due to the severity of his pain, he is not certain whether he performed six or seven rounds although the boy is certain they are seven.

If the case is as mentioned in the question, the pilgrimage is valid and the inquirer must not pay heed to any doubts he has.
And God Almighty knows best.