Help with dates!

[Tinkerbell124]

My last period date and due date doesn't match up!

My last period was 20th of April (break from the pill from the 18th - 25th)
I never went back on my pill after my pill break. If they dated my pregnancy from the first day of my lmp I should be due on the 25th if January with a rough conception of the 4th of May - instead I'm due on the 1st of February and I'm 27 weeks and 3 days which means means my period would have been a week later than it actually was, so I'm confused as to when I actually roughly conceived and how my dates don't match up when I had an early scan at 9 weeks which is supposed to be accurate

Hellllllp

 

[AP]

Due dates are give or take 2 weeks out. They are more based on the size of the baby at the dating scan than last period.

 

[tinkerbelle93]

It's totally normal.. my due date based on lmp was the 22nd december but the scan made it over a week later at 30th december, as pp said it's more based on the size of the baby, plus sometimes you may have ovulated earlier or later than usual which could affect it. xx

 

[ClairAye]

That's normal, based on my LMP I got a due date of January 10th, but I'm due 24th December and all 5 of my scans have indicated so

 

[Tinkerbell124]

So because my due date is later than I thought does that mean I ovulated later than I thought? Cause based on my lmp I should have ovulated around the 4th of May - wich means my due date would have been in January, but instead my due date is in February - and I had an eary scan and I've heard they are more accurate x

 

[AP]

No. It doesn't matter when you ovulated now. It's a rough estimate, first based on your last period until the dating scan. It's not an exact science really, babies come when they are ready, it's a rough date. The due date given at your dating scan has no baring on when you ovulated. The dating scans are accurate in terms of measuring your baby, not when you ovulated.

 

[dairymomma]

And some people just have smaller babies. My kids both measured 5-7 days smaller than my due date according to lmp my entire pregnancies. Also earlier ultrasounds aren't as accurate. That's because the baby is growing SO much during that first trimester and the measurements can vary according to how the baby is positioned, where it is in the uterus, the ultrasound machine, even the person doing the ultrasound and how they interpret the image on the screen. I've been told that if I went back in even later the same day and had another tech do the scan, I'd get a totally different set of measurements. I wouldn't worry.

 

[x__amour]

This is often why your first ultrasound is called a "dating scan" because we never quite know for sure when we ovulate. If I went by my last LMP, I would be due 04/26/2014 but with the size of baby, I'm due 05/04/2014. You should go by the EDD you were given by your OB/GYN.

 

[mayb_baby]

My dating scan says I am due 23rd April but LMP says 2nd of May and MW said we will go by my anomaly scan size as I am certain of my dates.

 

[dreamer_x]

Your doctor will give a rough estimate of how far along you are from your lmp, but that doesn't mean to say it's going to be very accurate, depending on when you ovulated. (Plus you have to take into account your cycle length - my cycle, even on the pill, wasn't terribly regular, some months it would be 28 days, others it would be 32/33, so I had no idea when I ovulated! Hence how I'm 27 weeks pregnant!)

Then when you go for your scan, all the lmp stuff goes out the window because as others have said, they then go off how big your baby is measuring.
If I went by my lmp, I would be due 26th January, but after my first scan, I was told baby was measuring a little behind that, so I was given a due date of 4th February.

So it's not going to match up with your lmp, but forget about that now, lmp is just a rough guideline at the beginning. Go on your scan dates!

 

[justhoping]

No. It doesn't matter when you ovulated now. It's a rough estimate, first based on your last period until the dating scan. It's not an exact science really, babies come when they are ready, it's a rough date. The due date given at your dating scan has no baring on when you ovulated. The dating scans are accurate in terms of measuring your baby, not when you ovulated.

^^ exactly and the due date is more of a guesstimate...they give u two weeks before the date and two weeks ater as a safe doorway to deliver so i wouldnt pay so much attention to the date...consider it ur due month....lol

good luck