ANSWER:

Purity is identified by seeing a white thread like discharge or by experiencing complete dryness. If you saw your purity once the flow of blood has stopped at the end of your usual period, you must take ghusl and disregard any spotting that comes afterwards as nothing, being keen to renew your wudhu before each prayer.

i have reached the day of my purity, i even saw a white milky discharge i usually see after my purity but i still had doubts and waited till the end of the day to be completely sure before taking ghusl and now i am having a faint yellowish discharge am disturbed maybe the yellowish is all part of purity & i must continue with my acts of worship.