My last period was on one date, scan is showing another week, and app says something else. I am totally confused when someone asks how many weeks. Which one should I follow?
It goes from the first day of your last menstrual period, not from conception. So count weeks from that date. The dating scan also confirms it accurately, so your gynac will tell you exactly at first visit.
Easiest way, count from the first day of your last period, thats how weeks are calculated. Or just put that date in any pregnancy app and it tells you the week and due date instantly. Thats what i did daily.
Doctors usually date it from your last period date, and the early ultrasound fine tunes it. If you're unsure of your dates, the scan is the most reliable. Best to let your gynac confirm the exact week.