Which app is more accurate?

opk +ve on Sep 3, then again +ve on Sep 10. That is if I ovulated on 3rd, My AF should have come after sep 13th, but As per my 2nd +ve opk, I should be getting my periods in another2 3 days.

My cycles are not regular. Usually 32-33 days.

My AF estimate as per each apps;

Glow - 12 days late

P tracker - 8 days late

Flo - expect in 2 days

ovulation calculator(OC)

Please help me decide which app is more reliable. Thanks! Baby dust to all!