Bismillahir Rahmaanir Raheem
Al Jawaab Billahit-Tawfeeq

Respected Sister,

It is permitted to take such birth control pills and other period-delaying medication to delay one's period during one's Hajj. However, it is best to let one's period run its course. The only action of Hajj directly affected by menstruation is tawaaf, and this is only significant with regards to the main obligatory tawaaf (tawaaf al-ziyaara), which is not permitted to be performed in the state of major ritual impurity, and if unperformed leaves one's Hajj unperformed and keeps one in the state of ihram. (Ibn Abidin, Radd al-Mukhtaar)

And Allah knows best.

Wassalam.