All perfect praise be to Allah, The Lord of The Worlds, and may His peace and blessings be upon our Prophet Mohammad and upon all his family and companions.
When yellowish or brownish discharges exceed fifteen days (Maximum of menstruation period), it is an Istihadah (Womb bleeding between periods) and not Hayd (Menstrual bleeding). In other words, it is not part of a woman`s monthly period. In this situation, a woman should calculate her old menses (Days and quantity) then observe fast and pray after making ablution for every prayer, even if the discharges continued.
If your (Questioner) monthly period, for example, is six days starting from the seventeenth of Ramadan, then you should consider these days as Hayd, and so you should make up only for the fast of these six days. As for other days, you should make up for the fast and the prayers, because you have stopped offering these acts of worship.
Therefore, you should perform them until it is time for your menses to start (Based on the calculation of your old menses). And Allah knows best.