I made Ghusl from menses and started performing prayer as I thought that the white discharge had appeared. However, I examined myself later and discovered that I was wrong and that the white discharge had not appeared yet. Should I stop praying, wait until it appears again, and then make Ghusl?

All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

If you have made Ghusl before seeing any of the two signs of purification (white discharge or dryness) and discovered that you have not become pure yet, then you should wait until you see any of those two signs and refrain from prayer and fast during this period. When you see either of the two signs of purification, you have to make Ghusl again because the first Ghusl was mistimed.