Anonymous asked in Pregnancy & ParentingPregnancy · 1 decade ago

Why do so many people say that pregnancy lasts 9 months when it actually lasts 10?

40 weeks = 10 months. I have always wondered why people say pregnancy is 9 months long. Can anybody tell me?

(My first pregnancy nearly went to 11 months.)

18 Answers

  • 1 decade ago
    Favourite answer

    some countrys have differnt counting

    for example you didn't have you menstration this july in the philippines it will be count nxt month

    while in japan it is counted as one month.

    some gave birth early and like in your case you gave birth so late.

    Source(s): i gave birth one month in advance before my due date
  • 1 decade ago

    It is 9 FULL months,

    month 1 1-4 weeks

    month 2 5- 8 weeks

    month 3 9-13 weeks

    month 4 14-17 weeks

    month 5 18-22 weeks

    month 6 23-27 weeks

    month 7 28 31 weeks

    month 8 32-35 weeks

    month 9 36-40 weeks.

    and also when doctors calculate pregnancy they start from the first day of your last period, most women do not concieve untill 14 days after their last period, and it take 2-3 days for implantion. you are not even pregnant for almost 3 of those 40 weeks.

    Source(s): my brain and the bok what to expect when your expecting :)
  • 1 decade ago

    This is because it DOESNT last 10 months! First, pregnancy is caluclated from the first day of your last period - you werent actually pregnant then - conception actually occurs about 2 weeks later - so in reality you are pregnant for 38 weeks - you are considered 2 weeks pregnant the day you conceive. It's dumb. Second, a month is not exactly 4 weeks. 4 weeks is 28 days. A month is 30-31 days, so every month is 4 and a half weeks. If you do the math, it works out to 9 months. Sorry to burst your bubble.

  • 1 decade ago

    I figured that out on my first pregnancy..BUT my doctor said u are not pregnant for 9 months or 10 months, just 40 weeks..LOL...thats what he said and I just stared at him..He said u cant count it in months u have to go by the 40 weeks..Sorry this didnt help at all. Best wishes.

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  • Anonymous
    1 decade ago

    The Drs. calculate pregnancy by lunar months, which are 4 weeks per month, but remember that there are some months of 5 weeks instead of 4. They make it this way 'cause is easy to be calculated.

  • 1 decade ago

    Ummmm... 40 weeks = 280 days. All but one month of the year has more than 28 days. 280 days is closer to 9 months than 10.

    Do the math!

  • 1 decade ago

    It depends on if you use 4 week months, which would equate to 10 months or calendar months which are really 4.33 weeks (52 weeks divided by 12 months). If you use 4.33 weeks, 40/4.33 is 9.2. That is where the 9 months comes from.

  • 1 decade ago

    actually exact time for women pregnancy is 9 months 9 days but it may vary before and after this time period.

    may God give u twins.


  • 1 decade ago

    LOL. Yes, we found this out too. It's very disappointing when you realize it about 8 months into your first pregnancy, and the whole pregnancy thing is getting a bit old anyway.

  • 1 decade ago

    They just say 9 months because that's the right amount of time for a baby too develop completely mentally and physically.

  • 1 decade ago

    Interesting question, I don't know the answer. However, it has been theorized that human pregnancy is actually getting shorter, and is actually closer to 38 weeks now.

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