She thinks that some impurity got onto her clothes; Are her Hajj and prayer invalidated by that?
Question

I had been to hajj When I was 6 months pregnant and once went to the toilet and feel that my clothes got dirty.But I didnt change as it was difficult in Mina and also because I had take water and wiped my clothes of.But I am still not sure if i was clean enough.Will my hajj be complete? or do i need to do hajj again?.
Praise be to Allah.Firstly: 
The impurity that got onto your clothes does not affect the validity of Hajj in sha Allah, because the essential parts of Hajj without which it is not complete are four: ihraam, which is the intention to do Hajj; Tawaaf al-Ifaadah; saa‘i between al-Safa and al-Marwah; and the standing in ‘Arafah. In the case of these four essential parts, it is not stipulated that one’s garment should be clean and pure, apart from what some scholars mentioned with regard to tawaaf, and that only applies in the case of one who is certain that there is some impurity (najaasah) on his body or garment. But in the case of any uncertainty, tawaaf is valid. 
Secondly: 
The Muslim does not have to change his clothes in the event that any impurity gets on to them. It is sufficient for him to remove that impurity with whatever means are available to him. And he should remember that the Shaytaan may open the door to waswasah (whispers) which may have no end, so he may whisper to him that the impurity has not been removed and that the garment has not been purified, hence his prayer is not valid, and so on, to fill him with worry, distress and anxiety until his entire life is ruined. 
Islam seeks to prevent this from happening to the Muslim in the first place, so it instructs him to dispel doubt and not pay any attention to it. 
It was narrated from ‘Abd-Allah ibn Zayd that a man complained to the Messenger of Allah (blessings and peace of Allah be upon him) that he thought that something had happened when he was praying, and he said: “Do not stop until you hear a sound or notice a smell.”
Narrated by al-Bukhaari (137) and Muslim (361). 
This hadeeth is the basis for the principle that “certainty is not dispelled except by an equal certainty.” The basic principle with regard to one who is praying is that he is taahir (pure) and should not stop praying unless he is certain that his wudoo’ is broken. 
The same applies in the case of the sister who asked the question: the basic principle with regard to her garment is that it was still pure (taahir), because she was not certain that there was any impurity on it. She says, “I feel that my clothes got dirty.” In that case, she is not certain that there was any impurity on her clothes. 
Based on that, if the Muslim is certain that there is any impurity on his body or garment, what he has to do is remove it, and it is not permissible for him to pray in that garment before he removes the impurity. If he is uncertain as to whether there is any impurity, then he should not pay any attention to it, because the basic principle is that there is no impurity and he does not have to do anything further if he prayed or circumambulated the Ka‘bah when this was the case. 
Shaykh Muhammad ibn Saalih al-‘Uthaymeen (may Allah have mercy on him) said: 
Islam – praise be to Allah – is complete in all aspects and is suited to the nature of man as Allah created him. It is a religion of ease and in fact came to keep man away from confusion, whispers and thoughts for which there is no basis. Based on that, the basic principle with regard to the individual and his garments is that they are pure, unless there is certainty that there is any impurity on his body or garments. This basic principle is attested to in the words of the Prophet (blessings and peace of Allah be upon him) when a man complained to him that he thought that he found something whilst praying – referring to minor impurity. The Prophet (blessings and peace of Allah be upon him) said: “Do not stop until you hear a sound or notice a smell.”. So the basic principle is that things remain as they are. 
With regard to clothes that people wear when entering bathrooms and relieving themselves – as mentioned in question – if they get damp, who can be certain that this dampness is caused by an impurity such as urine or water tainted with stools and the like? If we are not certain about that, then the basic principle is that things remain pure (taahir). It is true that he may think it most likely the case that it has been contaminated with something impure, but so long as we are not certain of that, then the basic principle is that it remains pure. 
So in answer to this question, we say: if they are not certain that their garments have got anything impure on them, then the basic principle is that they remain pure and they do not have to wash their garments. They can pray in them with no problem. And Allah knows best. End quote. 
Majmoo‘ Fataawa Ibn ‘Uthaymeen (11/question number 23)  
And Allah knows best.