What period date do I use?

My cycle is usually around 32 days, but I ovulated late (maybe?) so glow has pushed my period dates back. This is my first month <a href="https://play.google.com/store/apps/details?id=com.glow.android">tracking ovulation</a> using opk and I ovulated on cd26 (I am not sure if that is late for me since this is my first month tracking). So what date do I use as my period date to determine if I’m late? My original predicted date or the new one which is like a week later? I’ve never had a cycle as long as the glow predicated date.