Pregnancy dates and questions about conception/due date!?

Question

Hello! This would be my first time asking a questing here. I am currently pregnant... according to my dr, i'm 12 weeks five days pregnant. (That's from the ultrasound.) It's just confusing... i dont understand how they measure it and know how old it is. Anyway, my husband and i had sex on the 25th of november. (This would be a great time for us to actually conceive for personal reasons.) Is it possible this is when it happened? I'm sorry, i'm still getting used to these pregnancy numbers!
Just wanted to add...
Last period was 11/13/06.

Answer 1

they usually go from the first day of your last period. i never knew what mine was so they have always gone off the sonogram reading for my due dates. it's not an exact science. pretty much just a rough estimate.

Answer 2

I am also exactly 12 weeks 5 days, as I learned yesterday, (due on 8/25), although it sounds like your doctor may be off by a few days, just by counting. Yes, if you had sex on the 25th of November, this was likely your day of conception, since you had to conceive between 11/13 and the following month.

My last period was 11/18, and we know we conceived the week after thanksgiving. Hope it helps and congrats!

Answer 3

Yes if your last period was Nov 13th, then you usually ovulate 14 days after which would make Nov 25th the right time. They calculate it from November 13th, so the fisrt actual 2 weeks of pregnancy you arent pregnant It is the time from the period to conception. Your last menstrual period was 12 week and 5 days ago, but your babys gestational age would actually be 10 weeks and 5 days because that is when the baby was conceived.

Answer 4

Be very cautious when calculating conception and due dates based on your last period - everyone's cycle is different, and people don't always conceive at the right time within that cycle. I've seen discrepancies of up to 6 weeks in people basing due dates on when they last had their period. Your ultrasound dating is a lot more accurate, normally to +/- 5 days, as babies develop at a fairly constant rate. During the scan they measure the foetus from the rump to crown of the head (CRL), and the bi-parietal diameter (the width across the baby's head) (BPD). The CRL is more accurate up to about 13 weeks, then the BPD is more accurate up to about 36 weeks. They compare these measurements to growth charts to give a fairly good estimation as to how far along the baby is, and from there they can work out your estimated date of delivery (EDD).

Term is considered 38 - 42 weeks gestation (average 40). If you're 12+5 weeks, it means you're just entering your second trimester and you've got roughly 27 weeks/ 6 1/2 months to go. Your due date should be in mid August - about the 18th, but remember that full term babies can arrive two weeks either side of this. Don't forget your EDD is just an estimate. I know very few people who give birth spot on their EDD.

Answer 5

Anywhere from the 18th (going backwards from dates) through the 29th or so (likely the 25th-27th) based on your LMP.

At that age, they're measuring on the ultrasound in millimeters. They measure certain bones (the long bones, mostly) to give an estimate. This is adjusted sometimes.

In your case there's about a week's difference between the LMP date (which I trust more) and the ultrasound date (which has varying accuracy), BUT it doesn't really matter. It's early enough and the week difference doesn't really matter.

If you want more information, look up 'pregnancy calculator' in a search engine. There are various ones out there that let you plug in different numbers that you have.

Answer 6

First day of last menstrual period: November 13, 2006
Estimated date of conception: Monday, November 27, 2006
End of 1st trimester (12 weeks): Monday, February 5, 2007
End of 2nd trimester (27 weeks): Monday, May 21, 2007
Estimated Due Date: August 20, 2007

I done the above by putting in the first day of your last period in at: http://www.mybirthcare.com/calculator.asp
Good luck and Congrats!

Even though you had sex on the 25th and it says that you conceived on the 27th remember that sperm can live inside of you for up to seven days so you could have not gotten pregnant until 2 days later)

Answer 7

yup thats when it happend. go to www.baby-gaga.com
and pregnancy tickers. they have a due date calculator i typed in that your last period was 11/13/06 and it says you are 13weeks (may be off a few days) but you can change it to the due date your doctor gave you.

and www.babycenter.com has a lot of info on how they measure the gestational age of the baby, explaining how old the baby is and everything.

with the ultrasound they figure the due date by the measurments of the baby, how long the bones are and such. i think www.babycenter.com has more info on it. hope those sites help.

Answer 8

given you last period your conception date would be approx. 11/27/06 and you due date should be somewhere around 8/20/07. hope this helps. its just an estimate but sounds like the 25th could be the day.

Answer 9

Going by dates is just a guesstimation. It assumes that you ovulate 14 days into your cycle. Everyone is different. So again, the only way to know for sure is if you were usuing ovulation prediction kits or were charting and saw your spike. You can just say you conceived on the 25th if its that important to you. Best of luck.

Answer 10

THAT IS MOST PROBABLY WHEN YOU CONCEIVED. 12 DAYS AFTER YOUR PERIOD IS A VERY FERTILE TIME. WHEN YOU MISS YOUR PERIOD YOU ARE CLASSED AS FOUR WEEKS PREGNANT EVEN THOUGH YOU ONLY CONCEIVED TWO WEEKS EALIER! CONGRATULATIONS AND GOOD LUCK!