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 is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
If it is only a few drops of blood that come out of the womb of the woman, they are not considered as menses according to the majority of scholars as these drops are lesser than the smallest menstruation. However, the Shaafi'ee and
As regards whether she should continue the Tawaaf (circumambulation around the Ka'bah) or stop and make ablution, then according to the view of the scholars it is a condition requiring ablution to be free from any impurity so that the Tawaaf is valid. If someone's ablution becomes void while circumambulating the Ka'bah, he/she has to stop and make ablution and then complete the number of circumambulations, but if one starts from the beginning, then that is better. Some jurists consider that it is valid for a person to make the circumambulation even without being in the state of ablution. This is the view of the Hanafi school, but they consider that it is an obligation to make it up again as long as one is still in Makkah, otherwise he has to offer a sacrifice.
For more benefit, please refer to Fatwa: 83526 regarding the ruling of taking pills to prevent the menses, and Fatwa: 82627 about the ruling on woman circumambulating in menses.
Allaah knows best.