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LMP OR ULTRASOUND DUE DATE ?
my question is , should i go by my ultrasound due date or LMP due date  ?
so, according to my period which was may 1st ( i know this for sure ) i would be due febuary 5th . this was the date ive been given for half of my pregnancy . but when i had my ultrasound at 19 weeks and some days, the ultrasound tech said the baby was measuring 18 weeks , which would change my due date to febuary 15th.  at my appointment my doctor said we would stick to my original date of feb. 5th , but then the next time i went, he went by the 15th date . so im just really confused as to which date i should go by  . it doesnt really matter to me which date it is but my first son was born premeture and i would like to know how far along i am , just incase i were to go into labour early again . people have told me that the earlier ultrasounds are the most accurate but since i had mine at 19 weeks i thought it shouldnt really matter if the baby was a week smaller or bigger . what do you think  ?
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1420648 tn?1295813433
Go by the ultrasound date, you don't always ovulate when you think you do which would have put your date back
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202436 tn?1326477933
You should go with the original due date.  2nd and 3rd trimester ultrasounds can be off by 1 or 2 weeks either way.  If your doctor has changed your due date you should speak with him and ask him why.  The 1st trimester ultrasounds are the most accurate for dating.  Once you get into the 2nd and 3rd trimesters the measurements are based against "average" babies of that age and since babies begin to grow at different rates in the 2nd trimester it's not unusual for the dates to be off.  I'm curious as to why your doctor would refer to a new due date just based on the ultrasound being off by 1 week.  
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thanks thats what i thought also , and another i was just thought about . when i was pregnant with my first boy i didnt understand what lmp was , i thought it was the day your last period ended  . so i gave the doctor the wrong date i was off by about a week . so i had my ultrasound at what i thought was 18 weeks but really i was 19 weeks and they never said the baby was measuring big/small . so i guess that just shows babys can range in size  ?
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1194973 tn?1385507504
I agree. Go by the first due date. As said, later ultrasounds are not as accurate as early ultrasounds and can measure off.
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280369 tn?1316705641
This happened to me as well, but I always stuck with the original due date since it was done in the first trimester. Once in the 2nd and 3rd trimester, it will always fluctuate a little by a week or two. So I would say go by the first due date as well.  
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I had a scan in the first trimester which was dead on to my lmp for due date, but I had another scan at 19 weeks and the baby measured 18 and 2 days, my doctor did not change my due date he just said she may go over.  
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