When to test...

Miranda • Trying for my rainbow after losing my angel. Still born at 39 weeks 2/16/2016
Ovia originally said af was due last monday, i tested and BFN, so I went with Ovias day that said I was supposed to start July 1st, but I didn't start, and glow changed the start date to july 4... Still no period and I'm wondering when I should test.