how accurate is the weeks on any app?

Araceli β€’ Mommy of 3 girls. Married for 7 years. Baby #4 due August 12th πŸ‘ΆπŸΌπŸ˜
Hey ladies according to the app I am 8w 2d.. has it been pretty accurate for you guys? I have my first appointment next week but just curious about the accuracy! Let me know πŸ˜ƒ