Praise be to Allah.
Qatadah narrated that Anas (may Allah be pleased with him) told him that the Messenger of Allah (peace and blessings of Allah be upon him) performed ‘Umrah four times, all of them in Dhu’l-Qi’dah apart from the ‘Umrah which he performed with his Hajj. He performed ‘Umrah from al-Hudaybiyah or at the time of al-Hudaybiyah in Dhu’l-Qi’dah; (he did) ‘Umrah the following year in Dhu’l-Qi’dah; and (he did) ‘Umrah from Ja’rranah when he shared out the booty of Hunayn in Dhu’l-Qi’dah. (Narrated by al-Bukhari, al-Hajj, 1654; Muslim, al-Hajj, 1253)
Ibn al-Qayyim said:
“He did ‘Umrah four times after the Hijrah, four ‘Umrahs, all of them in Dhu’l-Qi’dah.
The first was the ‘Umrah of al-Hudaybiyah, which was the first of them, in 6 AH, but the mushrikin prevented him from reaching the House (the Ka’bah), so he offered the sacrifice (of camels) when his way was blocked at al-Hudaybiyah, and he and his Companions shaved their heads and exited the state of ihram, and went back in the same year to Madinah.
The second was the Fulfilled ‘Umrah in the following year, when he entered Makkah and stayed there for three (days), then he left after completing his ‘Umrah .
The third was the ‘Umrah which he did along with his Hajj.
The fourth was his ‘Umrah from al-Ja’rranah, when he went out to Hunayn then he came back to Makkah and performed ‘Umrah from al-Ja’rranah.
He said: there is no (scholarly) dispute concerning the fact that he did no more than four ‘Umrahs.” (Zad al-Ma’ad, vol. 2, p. 90-93)
“The scholars said: the Prophet (peace and blessings of Allah be upon him) performed these ‘Umrahs in Dhu’l-Qid’ah because of the virtue of this month and in order to go against the (ways of) Jahiliyyah. They used to think that this (i.e., doing ‘Umrah in Dhu’l-Qi’dah) was one of the most evil of evil actions, as stated above.
So the Prophet (peace and blessings of Allah be upon him) did that several times in this month as this was the most eloquent way of explaining that it was permissible and of demonstrating the beliefs of Jahiliyyah to be false.” (Sharh Muslim, 8/235)
And Allah knows best.