All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
Scholars have different opinions regarding the number of blows. Some say there will be three: the blow of terror, the blow of daze, and the blow of resurrection.
However the predominant opinion is that there will be three blows. This is indicated by the Hadeeth that is narrated on the authority of Abu Hurayrah that the Prophet, sallallaahu ‘alayhi wa sallam, said that the trumpet will be blown three times: the first will be the blow of terror, the second the blow of daze and the third the blow of resurrection. [At-Tabari and Ath-Tha‘labi:] [Ibn Al-‘Arabi: Saheeh (Authentic)]
Also, Ibn Katheer mentioned these after mentioning the Hadeeth that states that when the trumpet is blown everyone who hears it will listen carefully. [Muslim] First the blow of terror, then the blow of daze, which will cause the death of all living creatures, and then the blow of resurrection.
Allaah Knows best.