How do they estimate due date with a 30 day cycle?

Question

My midwife says I’m 6 weeks pregnant based on LMP, my cycles usually last 30 days.
I know I ovulated on 30th september, which would only make me 4 weeks. How do they calculate if you don’t have a regular 28 day cycle?

Answer

Due date is calculated from the first day of your last period. Not ovulation date.

Answer

Cycle length does not matter. Just count from last menstrual cycle.

Answer

They just modify off fetus size. 2 days will probably hold the same due date as a 28 day cycle. I had a 10 day difference and they just shifted it based on her size. According to lmp i was due May 28th but they said according to her size i was due june 5th.

Answer

I am in the same boat! My LMP would have put me due on May 19, but at the time of my ultra sound based on the babies growth, they set my due date as May 26th.

Answer

I believe they still use last period date which doesn’t make sense for people that don’t have perfectly timed cycles, they’ll probably have to adjust after scan and maybe after ovulation date if your share that info with/can convince 
 your provider. This shows how due dates are estimates!

How do they estimate due date with a 30 day cycle?

Let’s Glow

Glow is here for you on your path to pregnancy

25+ million

4.8 stars

20+

Getting Pregnant

Pregnancy

1st Year (Baby & You)

Baby Products