Is it obligatory to perform a specific ghusl with the intention of purification from semen that was discharged previously, if one was unaware of the obligation of ghusl from it? And is the ghusl for menstruation sufficient for ghusl from seminal discharge without an intention for it? And does semen discharge occur during menstruation?

A ritual bath (ghusl) performed with the intention of purification or removing ritual impurity (janabah) achieves purity and lifts the previous state of janabah, even if its cause recurred. If a woman needs to perform ghusl for both janabah and menstruation (hayd) and she intends both with a single ghusl, this is sufficient according to the majority of scholars. If she intends only one of them without the other, then for someone prone to obsessive doubts (waswasah), it is more lenient to consider the ghusl for menstruation sufficient for janabah, to avoid waswasah. As for the emission of semen during menstruation, it does not necessitate an additional ghusl; rather, one ghusl after the cessation of menstruation is sufficient to cover both janabah and hayd.