thread: Calculating EDD?

  1. #1
    Registered User

    May 2005
    Mt Evelyn
    65

    Calculating EDD?

    Hi girls,

    Just found out we are expecting bub #2 and just wondering about EDD. My last period date was 4th September (which I know is when you normaly calculate from) but I didn't ovulate til either 7th or 8th of October (yes a long cycle girl!). So do I calculate from then?

    I didn't know when O'ed with DS so I just went from period date! So this is all new to me!

    TIA!

  2. #2
    Registered User

    Jun 2006
    Melbourne
    705

    I Ovualted on the 6th of oct and FF is saying if I am pg that my EDD is the 29th of june!

    I hope that helps

  3. #3
    Registered User

    Sep 2006
    Carrum Downs
    344

    Hi Mellymac!

    You might be best to do the 4th Sept and ask your Dr for an early ultra sound.

    I was 3rd Sept, so my EDD is 10th June. But this changes anyway when you have your 13 and 18 week ultra sounds when the baby is formed and they can measure.

    So for now, being so early, I wouldn't stress about it and just take it from your last cycle date, explain your long cycles to your Dr and see what he/she sugguests??

  4. #4
    Registered User

    Feb 2004
    Melbourne
    11,171

    I would use the same theory as Fletch.

    They say that you are "2wks pregnant" when you ovulate assuming you ovulate on CD14.
    Soooo I would base it on that.

    Your LMP in theory was 23rd Sept, ovulation on the 7th of October, so EDD would be 1st of July or there abouts.

  5. #5
    BellyBelly Life Member

    Jan 2005
    in the valley of cuddles with mountains of smiles
    2,369

    I would definately ask your Dr for dating scan -as Tashie said - to be sure as your cycle is very long or you might be further along than you think ?

  6. #6
    Registered User

    Jan 2006
    8,369

    Mel, get an early U/S. I'm another long cycle girl who found out she was having a "normal" cycle this time round after an U/S - and we did ask the sonographer that it definately was that gestation, not 2 weeks earlier! But go with the latest EDD you possibly can, that will make you a lot less jumpy when the early ones come and go.

    The BBC website has a pregnancy calendar that allows you to put in your date of conception; that will be able to give you an EDD based on that. However, it really doesn't like anything but a 28-day cycle, so I have to use my EDC, not my LMP, for figuring stuff out on that.

  7. #7
    Registered User

    Feb 2005
    SA, Australia
    312

    Definately get an early U/S, with a cycle so long, makes it alittle difficult to work out.

  8. #8
    Registered User

    May 2005
    Mt Evelyn
    65

    Thanks for the advice girls!

    I have a doc appt tomorrow so I guess I wil have a chat to him about it - although I know he is not a huge fan of non-standard US.

    Just wondering though I tested at 9 DPO and the line was very dark and came up straightaway - so leads me to believe I am further along but I got a positive OPK on 6th October so would have assumed that to be correct? So confusing!!

  9. #9
    Registered User

    Jan 2006
    8,369

    The OPK detects hormone surges - it can also pick up a pregnancy before the hCG kicks in for the HPT - good luck with finding out how far along you are! Maybe a blood test for hormone levels could help?

  10. #10
    Registered User

    Jul 2006
    1,055

    Hi Mel,

    Congratulations on your pregnancy.....Its probably too late now seen as your going to the Dr's tomorrow but I have found a website that calculates EDD and you can adjust the length of your cycle from 20-44. Email me if you want me to send you the address

  11. #11
    Registered User

    May 2005
    Mt Evelyn
    65

    mmm...thats very interesting Ryn! I didn't know that about OPK's...its got me thinking now. I have been feeling sick (like my first pg morning sickness) for over a week and I guess that would be unlikely if I has had only just O'ed!?

  12. #12
    BellyBelly Life Member

    Jan 2005
    in the valley of cuddles with mountains of smiles
    2,369

    I agree with Ryn's suggestion + opk was BFP

  13. #13
    Registered User

    Jan 2006
    8,369

    I only know that because of the "OPKs as HPTs" threads on the conception boards! Good luck with being about 5 weeks gone rather than just the four!

  14. #14

    Jun 2006
    Penrith, NSW
    1,979

    I also had a long cycle - didn't o until CD 26 and then i'm pretty sure implantation didn't occur until 10DPO due to temp dip so according to my LMP i should be almost 2 weeks further along than i am. I told my GP that i was charting and was aware of ovulation being late so at what i thought was 8 weeks i was sent for a dating u/s and what do you know...i was correct to the day Blood tests at 4 weeks also helped determine that i actually wasn't 6 weeks preg as LMP suggested as HCG levels were too low to be that far along. It also helped for me that i suddenly got m/s at 6 weeks on the dot with my DD and the same thing happened this time around - so for me m/s was a good dating indicator.