When to test

DeAngela • Mommy of 2 👩‍👧‍👧 💍 wife

I have two apps i follow on my phone. One say my period suppose to come September 4 and one says my period suppose to come on September 9th, but neither one is accurate. My period is always between 20-22 days and today is 23 should i test or wait till the 9th?