LMP Due Date vs. Actual Due Date

posted 3 years ago in Pregnancy
Post # 3
359 posts
Helper bee
  • Wedding: July 2011

@isthisreallyreal:  my due date was estimated to be 9/4 based on lmp but I have longer cycles, around 34-35 days so after my ultrasound it got moved to 9/10. So… 6 days difference. 

Post # 4
994 posts
Busy bee
  • Wedding: June 2012

My original edd was jan 4 but I have really long cycles and I knew there was no way that was right. A first trimester ultrasound changed my edd to jan 24. A first trimester ultra sound is more accurate than the lmp. But don’t worry about your edd too much it’s just a guess my LO still isn’t here. There’s another page with good info about this but I can’t find it at the moment if I do I’ll post it. Congratulations


Post # 6
11772 posts
Sugar Beekeeper
  • Wedding: May 2013

They went by LMP and have not changed my EDD yet! I’m just shy of 39 weeks.

Post # 7
370 posts
Helper bee
  • Wedding: June 2013

Mine also went by LMP, mine are usually pretty regular.  My first few ultrasounds were behind a couple days, so I probably ovulated or implanted a bit later, but my office doesn’t change due dates unless they are more than a week off.

Post # 8
416 posts
Helper bee
  • Wedding: April 2011

They go by LMP unless your first ultrasound is far off.  My office uses 5 days in first trimester, 10 days in second trimester, or 15 days in third trimester.  Other places use use one week per trimester.  If your ultrasound dating is within those amounts, then your doc will keep your LMP dating.  Otherwise they’ll change it.

Post # 9
3787 posts
Honey bee
  • Wedding: June 2011

I just got my BFP yesterday, but the LMP date would be off my ovulation date by anywhere between 2-4 days. (I’m pretty sure it’s closer to 2, but there was some back on forth on my chart about which date was O.) I plan to just tell the doctor/midwife (haven’t decided) that my LMP was 14 days before the latest date. 

Post # 10
440 posts
Helper bee
  • Wedding: November 1999

@isthisreallyreal:  So I have sort of the opposite experience of my doctor saying my due date is earlier than I think.  I was tracking ovulation and know when I ovulated.  Based on that I think my due date is September 5th.  My ultrasound at 7w3d showed the baby the size of 7w6d which put me within a week, barely, of when my due date would be based on my LMP.  My doctor put my due date at August 26th (my birhday!) but in my head I still think it’s September 5th.  Oh well.

Post # 11
3119 posts
Sugar bee
  • Wedding: August 2012

I’m 11 weeks now, and when I went for an 8 week dating ultrasound, I measured exactly the same as my LMP. I have pretty average cycles, so I guess that isn’t too surprising. 

Post # 12
3394 posts
Sugar bee
  • Wedding: April 2014

@isthisreallyreal:  My doctor’s date was always a couple days before or after mine for some reason (I had all different doctors), but even that was never right. I think I ovulate earlier than normal because all 5 of my kids were born 4-14 days before my due date. MY last pregnancy they changed my due date further away twice after ultrasounds and he was born 2 solid weeks before the date the doctors finally settled on.

Post # 13
1805 posts
Buzzing bee
  • Wedding: November 2012

My due date based on lmp is 5 days earlier than based on ovulation date. the midwife is going with my lmp date Even though I measured 2 days behind at my first ultrasound.

Post # 14
671 posts
Busy bee
  • Wedding: December 2012

@PatientBee:  I am the same as you. At my last u/s I was 8w3d but was measuring at almost 9  weeks. I know I ovulated around cd11. They won’t change my due date which is 9/6.

Post # 15
8503 posts
Bumble Beekeeper
  • Wedding: September 2013

Mine was 3.5 weeks off but that is because I mistook implantation bleeding for my period.  Unfortunately by the time I found out I couldnt remember the date of my official lmp. But based on my guess my edd is within a few days of what a due date calculator says is my due date based on my guessed lmp.  A few days is close enough it doesn’t really matter.

Post # 16
440 posts
Helper bee
  • Wedding: November 1999

@amandasf: I ovulated lated, CD24.  I had only recently come of BCP.  It doesn’t really matter except that I really don’t want to be induced.  I’m a little worried I’ll be induced because I’m “two weeks late” when I think I’ll only be a few days late.

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