Due date question

Someonelikeyou · #1 (**permalink**) 09-15-2007, 07:31 AM

I apologize if I've posted this question in the wrong area. Please feel free to direct me elsewhere but 2WW is my home for the next week at least so I felt most comfy asking here

I was reading my "What to Expect when you're expecting" book last night and it explained how the pregnancy is aged at basically 2 weeks right from conception. Why is it done this way??? And what does this mean now when I read the rest of the book? For example, say I didn't find out I was pregnant until 2 wks after period was due. Since I know which date I would've conceived on, I'd know I was 4 wks pregnant and so I'd read the one-month chapter. But according to my book, I'd be 6-wks along and thus should already be reading the two-month chapter??

I know, I can (and most likely will) read both and all chapters lol, but still.........just wondering.

Constance_13 · #2 (**permalink**) 09-15-2007, 10:53 AM

It is very crazy how they do it BUT for lots of women then have no idea when they have actual conceived. So to keep everything standard and to give a base line to measure how far along you are at an U/S and to estimate a due date they start counting from the first day of your last CY. I know it does not make a lot of sense but they needed a way to standardize it.

If you find out you are PG 2 weeks after your CY is due you would be 6 weeks PG if your CY is 28d. If you have long or short CY it would need to be adjusted accordingly. So when looking online and reading your book you need to count from the day of your last CY to calculate your weeks along....if you don't you will be reading the wrong info about your body changes and where the baby is at in its development.

I hope that helps

Haras · #3 (**permalink**) 09-15-2007, 11:39 AM

That was a very good explanation, you put it better then my doctor.

Someonelikeyou · #4 (**permalink**) 09-15-2007, 08:56 PM

Thank you, that really WAS a great explanation

So, for us women that KNOW when we ovulated and/or KNOW the very day of conception..........do they take that instead........or do they still have to keep to the standardized formula?

It makes little sense to assume my would-be baby is 6 weeks when I KNOW it would only be 4 weeks, for example. I can see if I just didn't know...........

Constance_13 · #5 (**permalink**) 09-15-2007, 09:54 PM

I am so glad it made sense and that I could help

From my understanding they still use the "standard" formula as all the books, medical info, baby development, etc is based on this measurement.

Now they always say you are 7 weeks PG with a fetal age being 5 weeks.

At my early U/S the doc measured the baby at 7 weeks (fetal age 5 weeks in reality), I though I was 6 weeks 5 days, now its only 2 days difference and I believe that can be due to when the baby actually implanted. (We Knew exactly when I O'ed due to the trigger shoot but they still use the standard measurement). Marking me at 7 weeks is still with in line of the first day of my last CY...well off by 2 days now.

Its still kind of confuses me but that is my best understanding of it. I think they use the first day of your CY as the base line but different factors can change or adjust how far along you are and when you are due. I am guessing these factors are when you actually O, CY length and the actual implantation date. I believe these can affect the scale accordingly.

Good Luck, I hope you get your

very soon!!!!!!