Is what comes out of fluid when you come into contact with a woman (such as your mother) Mathi or Wadi? And is what you see on your garment a trace of this fluid or not? And are you required to perform Ghusl or not?

If the aforementioned fluid is discharged without desire, then it is likely a [case of] whispering (waswasa), and the default is that nothing has been discharged until proven otherwise. Certainty is not dispelled by doubt, and the default is for things to remain as they were.