How accurate was the <a href="https://play.google.com/store/apps/details?id=com.glow.android.nurture">due date calculator</a> you used online or on app compared to when you got your actual due date at your first prenatal appointment?

I have my first appointment is in a few weeks and I just want to know if i should expect a big difference from the date i calculated on the due date calculators!

Thank you!