Changing dates

Hi ladies. My cycle ALWAYS lasts 30 days. Not a day less, not a day more. We have been ttc since April (after a miscarriage) and glow is always spot on with AF. It has never been wrong. But this cycle I was finally able to track my ovulation. I got a positive opk on Aug 6th and logged it here. Right when I logged, glow change my period due daye for today, making my cycle 28 days. If I delete ovulation, it's back to 30 days. Now, AF hasn't showed. Should I test now or wait until Tuesday, which would be my original 30 days? Have you ladies noticed these changes?