Najis clothes

Brother i put najis clothes in washing machine with other clothes. my brother took his clothes out saying the are clean. The clothes were not washed now i doubt that his clothes might have made contact with my clothes and became najis.a day later I told my mum to wash that clothes, she took it out and placed it in a basket, that day it rained does the basket become najis. When the washed clothes are washed I place them in a basket and take to place it on rope. Please i need your help.