how did you count your weeks?

Madyne
Hi ladies, so I wanted to know how far along I would be before I went in for an appointment (I know it's very early on). My last period started on the 26 of March, and 40 weeks from that is roughly Dec 19th. But when I filled in my info in this app, it predicted my due date would be New Year's <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a>! Just curious to see what you guys did. Xoxo