Is fulfilling a vow I swore upon the Qur’an while menstruating obligatory, and what is the expiation if I wish to be released from it?

A woman's being in her menstrual period has no bearing on the ruling regarding fulfilling covenants and keeping secrets. If someone swears to fulfill a covenant and does not, an expiation for breaking an oath becomes obligatory upon them. It is obligatory for a person to keep a secret entrusted to them, based on the Prophet's (peace be upon him) saying: "There is no faith for one who has no trust (amanah), and no religion for one who has no covenant (ahd)," and his saying: "If a man tells a story and then turns around, it is a trust." It must be noted that it is not permissible for a woman to establish a friendship or similar relationship with a man who is not her mahram.