Q: What is the ruling on a person who doubted the number of rounds of Tawaf-ul-Qudum (circumambulation around the Ka`bah on arrival in Makkah)? Moreover, he performed Sa`y (going between Safa and Marwah during Hajj and `Umrah) after that.
A: If one doubts the number of rounds of Tawaf (circumambulation around the Ka`bah) after performing Tawaf or upon finishing it and moving to other acts, there will be no blame on him and his Tawaf will be valid.
But if one doubts the number of rounds while he is performing Tawaf, he has to complete his Tawaf. If one doubts the number of rounds to be either six or seven rounds, he has to perform the seventh round. But if one doubts the number of rounds after finishing Tawaf as if he thinks that he completed his Tawaf but Satan causes him to doubt his Tawaf, then his Tawaf will be valid.
Therefore, if doubting the number of rounds is at the time of Tawaf, one has to perform it again if it is Tawaf-ul-Qudum (circumambulation around the Ka`bah on arrival in Makkah) for those who come from abroad. Moreover, Tawaf-ul-Ifadah (final obligatory circumambulation around the Ka`bah in Hajj) will be sufficient for those who did not perform Tawaf-ul-Qudum if the pilgrim is performing Qiran Hajj (combining Hajj and `Umrah simultaneously) or Ifrad Hajj (performing Hajj only) and keeps the state of Ihram (ritual state for Hajj and `Umrah). But if one performs Tamattu` Hajj (combining Hajj and `Umrah with a break in between) and doubts the number of rounds of Tawaf-ul-Qudum at the time of performing them without making up for what he doubts, he will be regarded as if he did not perform Tawaf at all. In this case, his Hajj will be considered Qiran Hajj because his Tawaf will be come void. But if one doubts after finishing Tawaf, this doubt will be in vain because doubting after finishing acts of worship is to be disregarded.
[Fatawaa Shaykh Ibn Baaz - Alifta.net]