ANSWER:
You must not pay attention to such doubts if they come after you have performed the act of worship (wudu in your case) and especially if this (doubts) is a reoccurring thing for you.
ANSWER:
You must not pay attention to such doubts if they come after you have performed the act of worship (wudu in your case) and especially if this (doubts) is a reoccurring thing for you.