Sheikh Ahmad Kutty, a Senior Lecturer and Islamic Scholar at the Islamic Institute of Toronto, Ontario, Canada, states the following: According to the vast majority of scholars, while menstruating, the woman is not allowed to make Tawaf (circumambulation of the Ka`bah), which is a pillar of `Umrah, without which `Umrah is not valid. Therefore, if you’re a menstruating woman in pilgrimage, you should wait until you are free of menses and have purified yourself, then you can make `Umrah.

If you are already in Makkah and your menstrual period starts before you are able to make your `Umrah, you should wait there until it is over, and after having purified yourself you may go to tan`im, which is a place at which you can enter into ihram and enter Makkah with ihram. Otherwise, you may go to Madinah and visit the Prophet’s Mosque while you have your period and come back later to Makkah in ihram.
There are safe methods for putting off menstruation as a temporary measure, and there is nothing wrong in Shari`ah in making use of that.
However, in the case of Hajj (I mean the only Hajj you are able to perform) and you are forced to leave Makkah because of travel arrangements that you cannot change at all, then you’re allowed to make Tawaf and your Tawaf will be considered valid as an exceptional case. This is the ruling given by Imam ibn Taymiyyah (may Allah bless his soul).

Allah Almighty knows best.