I want Inshaa’Allaah to fast the first nine days of the month of Thul-Hijjah and break fasting on the tenth day along with slaughtering a sacrifice. How should I make my intention? Should I consider myself in a state of Ihraam (ritual consecration)? In case I menstruate during these nine days, will I still be rewarded?

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.

We ask Allaah The Almighty to help you fulfill what you intended and to reward you for this. As for the manner of making your intention, the real intention is what in the heart and its verbal utterance is not legally required. Rather, it is enough that one intends by the heart to do these acts of worship. It is also permissible for you neither to take from your hair nor to clip your nails until you slaughter your sacrifice.

As for your question about the reward if you are unable to observe fasting due to the menstrual period, Allaah The Almighty never allows the work of anyone to be lost. So, you will be rewarded for your righteous and good intention. The Prophet, sallallaahu ‘alayhi wa sallam, said: "Whoever intended to do some righteous deed and did not do it, Allaah will (nevertheless) record it as a complete good deed." [Al-Bukhari and Muslim]

Allaah Knows best.