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Krs · Sep 30, 2009, 11:54 PM

Why do we calculate the conception date from the date of your last period?
When you can conceive when you have you period, but when you ovulate after period?

Thanks

J_9 · Oct 1, 2009, 06:39 AM

I'll give you the simple textbook answer...

For example, let's say that the first day of your last period was September 1, ovulation typically would be on the 15th of September. At which time you were most likely to conceive. That would give you a due date of June 6.

It takes approximately 3 days for the sperm to travel up the vaginal canal, through the uterus and into the fallopian tubes where it is fertilized. Then it makes the trip back down to the uterus where the zygote implants, this can take another three days. Sperm can live in the vagina for up to 5 days before dying if they don't find an egg to fertilize.

What is your due date and I can possibly explain it better.

Krs · Oct 1, 2009, 07:04 AM

1st June 2010
My first day of last period was was on the 25th aug 2009

J_9 · Oct 1, 2009, 07:23 AM

You most likely conceived on or around September 8. Think back... did you have sex around that time?

Krs · Oct 2, 2009, 12:52 AM

Yes we did :)

Its just odd that its calculated from the first day of your last period...

Which makes me 5 weeks 3 days pregnant however really if we had sex around the 8th sept I'm 4 weeks pregnant..

Can't understand it hehe

J_9 · Oct 2, 2009, 06:07 AM

It's calculated this way because of hormone fluctuations before, during and after your period. The menstrual cycle (all month long) has surges of certain hormones while others fall to lower levels. This is like a wave effect that occurs the entire month. So, due to certain hormone levels at the beginning of the period, we can calculate approximately when you got pregnant.

It's the same calculation for every woman no matter how long her cycle is... ex: 28 days, 31 days, etc.

Krs · Oct 3, 2009, 01:12 AM

Thanks for your explanation I understand it now :)

Krs · Oct 13, 2009, 07:16 AM

Was just wondering so is my baby 7 weeks in the womb OR 5 weeks?

Im still unsure.
Am I 7 weeks pregnant or 5 weeks?

J_9 · Oct 13, 2009, 07:35 AM

As of today you are 6 weeks and 6 days. Tomorrow you will be exactly 7 weeks pregnant.

Krs · Oct 13, 2009, 07:57 AM

OK so in my womb my baby is grown 7 weeks come tomorrow?

Thanks

J_9 · Oct 13, 2009, 07:58 AM

Originally Posted by Krs

ok so in my womb my baby is grown 7 weeks come tomorrow?

Thanks

Yes, exactly. ;)

Krs · Oct 13, 2009, 07:59 AM

Wiiiiiiiiiiiiiii
Thank you J_9

It was abit hard to understand as I ovulated around 5 weeks ago.

J_9 · Oct 13, 2009, 08:01 AM

At least you THINK you ovulated 5 weeks ago. LOL, there is no way to tell for 100% certain.

Krs · Oct 15, 2009, 06:47 AM

Isn't obvious to ovualate 10 days after your first day of period though?
I think I'm engineering this too much... as in my mind if I ovualated 5 weeks ago that should be when I conceived not 7 weeks ago when I had my period?

Thanks

J_9 · Oct 15, 2009, 06:54 AM

Every woman ovulates at different times during their cycle. Not all women ovulate "10 days" after. Also, there can be variances due to certain situations... illness, weight loss or gain, diet and/or exercise change, stress, etc.

So, the easiest thing to do is go by the LMP (Last Menstrual Period).

I think you are over thinking this a bit.

Some women even have a "period" in early pregnancy because they got pregnant so early that the zygote (baby) was still in the fallopian tubes when it came time for the period. During or after the period the zygote moved down through the fallopian tubes where it implanted into the uterus making you further along than you thought you were.