LMP or ultrasound scan date?

Question

Do you go by your LMP or what ultrasound tech says for estimated due date? My Obgyn prefers LMP and that’s what I’ve been going by which makes me 19 weeks. But ultrasound tech says I’m a week behind.

Answer

You start with LMP. Then you have a dating scan between 8-12 weeks. As long as it is not more than a week different, you keep the due date from your LMP. Ultrasounds past 12 weeks are NOT good for dating as babies start growing at different rates after that.

Answer

My periods have always been very very regular so me and my OB always go by LMP