Nuvaring confusion

Bree

When do I start the Nuvaring again? I’ve been on the Nuvaring for a year now but for the first time, last month my period was late by 2 days and started on a Friday and I usually start my Nuvaring on the Sunday which I did. Well my period is supposed to start tomorrow and I usually start the ring on Sundays so do I start this Sunday or next Sunday?