The number of Umrahs performed by the prophet (saws) and when he performed them

Mujahid reported: I and 'Urwah b. Zubair entered the mosque and found 'Abdullah b. 'Umar sitting near the apartment of A'ishah and the people were observing the forenoon prayer (when the sun had sufficiently risen). We asked him about their prayer, and he said: It is bid'a (innovation), Urwah said to him: O Abu Abd al-Rahman, how many 'umrahs did Allah's Messenger (ﷺ) perform? He said: Four 'umrahs, one he performed during the month of Rajab. We were reluctant either to believe him or reject him. We heard the noise of brushing of her teeth by 'A'ishah in her apartment. 'Urwah said: Mother of the Faithful, are you not hearing what Abi 'Abd al-Rahman is saying? She said: What is he saying? Thereupon he ('Urwah) said: He (Ibn 'Umar) states that Allah's Apostle (ﷺ) performed four 'umrahs and one of them during the month of Rajab. Thereupon she remarked: May Allah have mercy upon Abu 'Abd al-Rahman. Never did Allah's Messenger (ﷺ) perform 'Umrah in which he did not accompany him, and he (Allah's Apostle) never performed 'Umrah during the month of Rajab.