Is what the questioner does correct in that she does not consider the brownish discharge that precedes menstruation by a day or two to be menstruation, and she prays until she sees blood, knowing that sometimes she experiences brownish discharge along with blood? What should she do regarding fasting if Ramadan comes?

Scholars differ on the ruling concerning yellowish and brownish discharges (ṣufra and kudra). The fatwa we adopt from their opinions is that of the Hanbalis, which states that brownish discharge is menstruation if it occurs during the accustomed period or if it is connected to blood. You may follow any of the scholars. So, whoever considers it menstruation absolutely should abandon prayer upon seeing it. And whoever does not consider it menstruation absolutely—like Ibn ‘Uthaymin—should not pay attention to it. However, if you wish to act upon our preferred view, then if the brownish discharge occurs during the accustomed period, it is menstruation, and you should abandon fasting and prayer for it. Otherwise, it is not considered menstruation, and you should perform istinjā’ (cleaning with water) and make ablution for prayer.