When should one perform ghusl and make up the Maghrib and Isha prayers when in doubt about seeing the white discharge or dryness after menstruation?

When in doubt about purity (tahara), the original state of menstruation remains. Do not deem yourself pure except with certainty. If you were not certain of purity before Fajr and you performed ghusl after it, you do not have to make up the prayers of Maghrib and Isha. However, if you were certain of purity before Fajr, then you must make up these two prayers immediately.