Rulling of doubts

When i urinate i usually do istinja twice i first wash mostly the exit part and the upper part and then i get up and flush the toilet and do an excessive istinja cause i have ocd but yesterday when u did my first istinja my blouse touched a part of my private part and i dont know if it touched the lower section or not i think it didnt but im not completely sure so do i just ignore this doubt? Since im not sure if any impurity touched my blouse or not and i know that certainty is not affected by doubt