During tawaaf he became unsure (of how many circuits he had completed), so he proceeded on the basis of what he thought was most likely to be the case. Is his tawaaf valid, or does he have to repeat it?
Question

I did Hajj this year, and on the day of Eid, after stoning Jamrat al-‘Aqabah, I went to al-Masjid al-Haraam and did tawaaf al-ifaadah. But during tawaaf, I became uncertain as to whether I had done four circuits or three? So I proceeded on the basis of the larger number, and I thought it most likely (to a great extent). Then I began to have doubts again when I was doing the sixth circuit: was this the sixth or the fifth? And I proceeded on the basis of the larger number, assuming that it was the sixth, as that is what I thought was most likely the case. Then I finished tawaaf and prayed behind the maqaam, then I prayed Jumu‘ah, believing that I had done seven circuits and there was no reason for doubt. On the second of the days of at-tashreeq I did tawaaf al-wadaa‘ (the farewell tawaaf) with the intention of doing tawaaf al-wadaa‘ only, then after I left Makkah I began to wonder whether it was possible that I had omitted any of the circuits of tawaaf al-ifaadah. Do I have to go back and repeat tawaaf or not? Please note that I live in Haa’il in Saudi. If I have to go back and do tawaaf again, do I have to put on ihram from the miqaat or not? Do I have to shave my head or not?
Praise be to Allah.Firstly:
We have previously explained that what one thinks most likely to be the case may be regarded as certainty with regard to rulings. Please see the answer to question no. 49667 .
Secondly:
Uncertainty regarding tawaaf must either arise after finishing it, or during it.
If it arises after having finished it, then it does not matter, unless one is certain about it on the basis of definitive evidence concerning which there can be no doubt.
If it arises during it, then if both options are equally likely and he does not think that one of them is more likely, he should proceed on the basis of the lower number. So if he is uncertain as to whether he has done five or six circuits, and he does not think that either is more likely than the other, then he should proceed on the basis of the lower number, which is five, and complete his tawaaf accordingly.
Please see the answer to question no. 171308
But if he thinks one of the two is more likely to be the case, he should proceed on that basis, by analogy with prayer, and he does not have to do anything else. So if he is not sure whether he has done five or six circuits, but he thinks it most likely that he has done six, then based on that he should do the seventh circuit, and his tawaaf will be valid, in sha Allah.
It was narrated by ‘Abd ar-Razzaaq in al-Musannaf (9810) and al-Faakihi in Akhbaar Makkah (603) that Ibn Jurayj said: I said to ‘Ata’: I am not sure about tawaaf, whether (I did) two or three circuits. He said: Proceed on the basis of what you think most likely to be the case. I said: I did tawaaf with another man, and we disagreed (on the number of circuits we had done). He said: The answer is the same. I said: Should we proceed on the basis of what we think most likely to be the case or the smaller number that we think? He said: Rather you should proceed on the basis of what you think most likely to be the case.
Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) said: If a person becomes unsure during tawaaf (as to how many circuits he has completed), should he proceed on the basis of what he is sure of or on the basis of what he thinks is most likely to be the case?
He replied:
There is a difference of scholarly opinion concerning that, like the difference concerning one who becomes uncertain as to how many rak‘ahs he has prayed. Some of the scholars said that he should proceed on the basis of what he thinks most likely to be the case, and others said that he should proceed on the basis of what he is certain of.
For example, during tawaaf a person becomes uncertain as to whether he has done five or six circuits. If both are equally likely, then he should assume that it is five, because that is more certain. If he thinks it most likely that it is five, then he should assume that it is five. But if he thinks it more likely that it is six, then some of the scholars say that he should proceed on that basis and assume that it is six, and other scholars say that he should proceed on the basis of that which is certain, and assume that it is five.
The correct view is that he should proceed on the basis of what he thinks most likely to be the case, as in the case of prayer. Based on that, he should assume that it is six, and do a seventh circuit.
But after having completed tawaaf and departed from the place of tawaaf, if uncertainty arises it does not matter and one should not pay any attention to it, so long as one is not certain about the matter.
End quote from ash-Sharh al-Mumti‘ (7/ 249)
Based on that, your tawaaf is valid and you do not have to do anything, in sha Allah.
And Allah knows best.