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Childbirth/why arent weeks adding up

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Expert: - 7/18/2009


Question
hi, well my question is why do the doctors start counting my pregnancy according to the last day of my lmp. rite now i am 26 weeks pregnant but when i count my weeks it doesn't add up. i also want to know when was it that i conceived,my due date is october 22 and my last lmp was jan.15
 thank you for your help .

Answer
Dating a pregnancy from the last period has been done for a long time - the date of your last period is something that is easily determined.  The exact date of conception is harder to determine (especially in the days before ultrasounds were used) so it was easier to date it from something that is easily known. I agree that is is very confusing, especially since it means that you weren't even pregnant during your 1st two weeks of pregnancy!

So if you are 26 weeks pregnant, it means you conceived approximately 24 weeks ago. Assuming you have 28 day cycles, you probably conceived between January 25-29.  If you tend to go longer than 28 days between periods, you probably conceived a little after that.

I hope that makes things a little less confusing!

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Dorothy H, LCCE

Expertise

As a certified childbirth educator and birth doula, I can answer questions dealing with preparing for birth, childbirth classes, pregnancy, what happens during labor and birth, doulas, VBAC, natural childbirth, cesarean birth, interventions in labor, labor, birth, helping someone through labor, concerns or fears about labor and birth, doulas, breastfeeding, and other topics dealing with pregnancy, labor, and birth.

Experience

Since 2004, I have taught childbirth education classes focused on helping couples gain confidence, make decisions for their birth, and give them tools for helping them get the birth they want. Since 2004, I have also attended births in local hospitals as a birth doula (as of 8/10, I have attended 120 births) so I am able to see firsthand what is working in helping couples deal with labor. I am also a mom of five children, and have various birth experiences myself, including unmedicated birth and a cesarean.

Organizations
Lamaze International DONA International

Publications
International Doula Magazine

Education/Credentials
I am a Lamaze-certified childbirth educator. I am a DONA-certified birth doula.

Past/Present Clients
I work with approximately 4-6 couples a month with my childbirth classes. I attend 2 births a month with doula clients.

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