Due date/ # weeks confusion

slc2b · October 2009

So when I use my lmp for calculating it says 5w1d. But when I use my ovulation/conception date it says 4w4d....which one is right? I guess it is only a few days different, but the diff between 4 and 5 seems like a lot to me right now! I know the ob will clear this all up for me but doesnt hurt to ask!

sweetbossom83 · October 2009

I got soooo frustrated with that! I just go by what the doc says haha. your lmp will show longer than ovulation/conception.

CaitlinJ22 · October 2009

usually OB's go by LMP, I knew when I conceived DS and it made my edd based on conception 4 days before my edd calculated by the doc by using my LMP. I had ds 5 days early (according to my LMP due date)..SO my conception due date was more accurate. so I know it sounds like it matters now, but I would go by your LMP due date for now, ask your doc, but in the end it doesnt matter too much.

CaitlinJ22 · October 2009

oh and they will confirm EDD at early u/s too.

BelhurstBride · October 2009

Your doctor will go by your LMP.

rlscheck · October 2009

The EDD based upon your last period assumes that you ovulated on the 14th of the month and had a 28 day cycle. My BFP cycle I started on Sept 1st, but through charting I know I didn't ovulated till CD 20- putting me 1 week behind the typical "ovulate on the 14th". Therefore I am more likely 5 weeks pregnant instead of 6. The calculations are crazy, I know!

eleventofive · October 2009

Typically the lmp method assumes you O'd on CD14. If you O'd on a different day, the due dates would be different. I have the same issue -- I O'd on CD17.

laurasue · October 2009

Your doc will use LMP but once you're measured at your ultrasound you will be closer to EDD using ovulation date. To avoid making yourself crazy thinking you're farther along than you are, I would go by O date.

slc2b · October 2009

rlscheck:
The EDD based upon your last period assumes that you ovulated on the 14th of the month and had a 28 day cycle. My BFP cycle I started on Sept 1st, but through charting I know I didn't ovulated till CD 20- putting me 1 week behind the typical "ovulate on the 14th". Therefore I am more likely 5 weeks pregnant instead of 6. The calculations are crazy, I know!

This is me! I o'd on cd 19 or 20, have always ovulated a bit late. Ah well, I will try not to think about it too much

KeepingFaith · October 2009

rlscheck:
The EDD based upon your last period assumes that you ovulated on the 14th of the month and had a 28 day cycle. My BFP cycle I started on Sept 1st, but through charting I know I didn't ovulated till CD 20- putting me 1 week behind the typical "ovulate on the 14th". Therefore I am more likely 5 weeks pregnant instead of 6. The calculations are crazy, I know!

This

Also just to clerify conception and when you Oed are not the same thing. So if you know when you Ovulated thats one thing, but conception will not give you a due date

slc2b · October 2009

KeepingFaith:

This

Also just to clerify conception and when you Oed are not the same thing. So if you know when you Ovulated thats one thing, but conception will not give you a due date

Thanks I know it isn't the same thing, but I figure they couldn't be too far apart...

bnljane1988 · October 2009

At first my Dr. goes by the LMP. But then he does a U/S pretty early and dates by that. My U/S at what we thought was 6.5 weeks, dated me back to just over 5 weeks - we saw the heartbeat, so there was no worry.

synchrosally · October 2009

Yup. Ditto! Even when I told my doctor that I thought my EDD would be June 15 based on my cycles, he said, nope, it's June 8, though since this is your first, you'll probably go late and it will end up being more like June 15. I don't know. I just went with what Dr said and I'll wait for the u/s to confirm at 12 weeks.

Want a personalized experience?

Due date/ # weeks confusion

Re: Due date/ # weeks confusion

Choose Another Board

Search Boards