While in a state of menstruation, it is prohibited to enter the mosque and it is unlawful to make tawaf.
If you are in a state of iḥrām for umrah and your menstruation starts BEFORE you begin performing your umrah ṭawāf, then you must wait until your menstruation finishes before entering the mosque and making ṭawāf.
If you are in a state of iḥrām for umrah and your menstruation starts DURING the performance of your umrah ṭawāf, then you must leave the mosque immediately and wait until your menstruation finishes before completing your ṭawāf.
If your group will leave Makkah before your menstruation finishes, then you must contact a scholar/mufti about what to do in your situation.
BE RESPONSIBLE and plan ahead of time. Read about taking medication to stop your bleeding during the days that you’re in Makkah here inshaAllah.