how are you calculating your EDD?

lovin life23 · May 2011

Okay, So with PCOS my cycles were usually 35-45 day cycles. May was the first cycle after 3 months of not Oing that I actually O'd! My LMP was April 18th and I didnt O until CD19 on May 6/7th (got +opk may 6th bd'd that night and the night after) I know, I know..but I was taking a break from temping. got my bfp CD 30. I would like to use May 6 or 7th as my conception date...since my cycle was 30 days long. That would put me at 4 weeks rather than 5 +2 days.....

Question: are you using your "O-date" or LMP to predict EDD...or, if you have a confirmed EDD from you dr. was it in line with the date you predicted? (if so, what did you predict it from, O date or LMP? Thanks!!

meganruns · May 2011

I used my O date to figure my EDD since my body had fallen in the habit of O'ing late recently. My first appointment is Friday, and by my calculations, I should be 7 weeks exactly. We'll see how it lines up with the u/s.

bigbear · May 2011

Unless you know exactly when you O'd i would go by the LMP date. I am going by my LMP date as the month I got pregnant I actually didn't temp or anything else - go figure lol. But I think I would have gone by my LMP date regardless. That's what the doc always asks, too so I figured it's easier...

eklanger · May 2011

I'm going by my LMP but according to FF I O'd on day 14 so it wouldn't really matter either way for me.

Dani182000 · May 2011

I actually temped the cycle I got my bfp so I am using my o date because I know the exact day. My doctor is tenativly using my LMP which is three days later then when I use my o date. I have a dating ultrasound on June 2 so we will see who is closer Smile

ginger514 · May 2011

My LMP put me with an EDD of 12/28/11, but I have 34 day cycles and usually O on CD 19 or 20 so I was thinking the first week of January. Plus we only were able to have sex one time during April, so I knew around the time we conceived. The doctor used my LMP until I had my ultrasound, which moved my EDD to January 3rd which was exactly in line with my thoughts. I would just make sure the dr. knows about the length of your cycles and it will most likely be confirmed with an ultrasound.

starrynyt · May 2011

I'm using the day after O. I O'ed oddly early this cycle (CD 8) so there's only one possible day that we could have conceived because we weren't trying yet given how darn early it was. I'm basing it off that for now, but we'll see what my RE has to say at my u/s tomorrow. I forsee a battle even though basing it off my LMP would be off by almost a whole week.

rachoochoo2 · May 2011

I replied in your other thread too but with irregular cycles I would use your O date since it will be more accurate. LMP is great if you have a perfect 28 day cycle and always O on CD 14.

selena61307 · May 2011

I am using my O date, I was temping and I O'd a few days late so my midwife agreed to use my calculations.

lovin life23 · May 2011

I only ask b/c I have an appt next tuesday at 6wks 1 day based on LMP but from O date I think its maybe 5 weeks?...I'm so confused...

illinigal · May 2011

I did IVF, so I used egg retrieval date, which would correlate to O date. Then add 266 days. I have my first ultrasound tomorrow, so hopefully they'll confirm the EDD then.

MrsMeMo · May 2011

The majority of doctors will go by your LMP unless going by your O date changes the date by a week or more.

ginger514 · May 2011

lovin life23:
I only ask b/c I have an appt next tuesday at 6wks 1 day based on LMP but from O date I think its maybe 5 weeks?...I'm so confused...

I think it's pretty normal to be confused. Go by your LMP for now, which is what I suspect the doctor will do, and just let them know that you think you may not be that far along. They will likely order a dating/viability ultrasound just to confirm. I've read that the EDD can change a number of times, especially in early pregnancy, so I would not worry too much about it Smile

ajwilkers04 · May 2011

I also have PCOS and it's much better to go with your O date. Your first ultrasound will give you a better idea. I've had 3 so far and gotten 3 different dates at each one, but they are within a 4 day range, so I split the difference. We were also taking a break when we got a BFP so I'm not 100% sure of when I O'd but I have an idea. But if I went with LMP I would be 2 weeks further along, which is way off and I'd be terrified b/c I would be measuring 2 weeks behind, so go with O.

ames243567 · May 2011

I am using what FF told me which is my O date which was CD 17. I meet with my Dr in a week and a half so we will see what she says!

talitha712 · May 2011

My dr is using my LMP, which gives me a due date 4 days earlier than my O date (I O'd on CD18). My u/s today lined up with my O date, but they still have 1/7/12 as my EDD instead of 1/11. We'll see what my upcoming ultrasounds and appointments bring.

anhg80 · May 2011

I'm using my O date, although my doctor is using my LMP. I O'd on CD 20, so I'm ready to hear that I'm measuring "behind" at my first ultrasound. I think, at this point, you can choose either. Eventually, your doctor will give you a firmer answer, and you can switch.