Why do we calculate the length of a pregnancy from the first day of a women’s last period?

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Why do we calculate the length of a pregnancy from the first day of a women’s last period?

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Anonymous 0 Comments

I’ve got a different question about pregnancy. If average gestation period is 40 weeks, why does everyone say human pregnancy is 9 months? 40 weeks is 10 months.

Anonymous 0 Comments

Every time you have your period it is your body getting ready for the next opportunity to get pregnant. Your period is always day 1 in your cycle. It’s difficult to calculate the day you ovulated or the day the egg got fertilized so it’s just easier to know what day you began your period.

Anonymous 0 Comments

I’ve got a different question about pregnancy. If average gestation period is 40 weeks, why does everyone say human pregnancy is 9 months? 40 weeks is 10 months.

Anonymous 0 Comments

I’ve got a different question about pregnancy. If average gestation period is 40 weeks, why does everyone say human pregnancy is 9 months? 40 weeks is 10 months.

Anonymous 0 Comments

Every time you have your period it is your body getting ready for the next opportunity to get pregnant. Your period is always day 1 in your cycle. It’s difficult to calculate the day you ovulated or the day the egg got fertilized so it’s just easier to know what day you began your period.

Anonymous 0 Comments

Every time you have your period it is your body getting ready for the next opportunity to get pregnant. Your period is always day 1 in your cycle. It’s difficult to calculate the day you ovulated or the day the egg got fertilized so it’s just easier to know what day you began your period.

Anonymous 0 Comments

because that’s the only date of the cycle known for sure. neither the date of ovulation, nor date of fertilization are known for sure, unless it is a rare single-time intercourse like in case of rape, but the observations and conclusions were made primarily on average women who have survived the first delivery already

Anonymous 0 Comments

What’s really annoying is that even if you conceive by artificial insemination and know the actual day of conception, they ignore that and still use the date from your last cycle.

Anonymous 0 Comments

If a woman is experiencing normal menstrual cycles, then her body exists in one of two states:

1) Preparing to be pregnant
2) Flushing the System

The system is flushed during her period. After that period ends, she is again preparing to be pregnant. The first step is preparing the uterus for the impending fertilized egg. The uterine lining will thicken. The fertilized egg showing up is just one step of many.

After a certain amount of time of the egg not showing up, this potential pregnancy is declared void and the woman then reenters the flushing the system state and the clock starts over.

Pregnancy is more than just the development that occurs to the zygote/embryo/fetus. The changes to the uterus that occur for pregnancy start after the last period ends. This will be at least a week before the introduction of sperm via intercourse or other means, and at least three weeks before the missed period that is the first signal most women get that they might be pregnant.

The best analogy I have is that you have a guest coming to stay, so you decide to build them a house for them to stay in. They may have come to visit you 2 weeks after you started building the house, and they may not have even let you know they were around for another 2 weeks, but when they leave the house you built them 36 weeks later, that house still stood for 40 weeks, not 36.

This is the “standard” cycle and “standard” pregnancy. There is a lot of variation.

Anonymous 0 Comments

because that’s the only date of the cycle known for sure. neither the date of ovulation, nor date of fertilization are known for sure, unless it is a rare single-time intercourse like in case of rape, but the observations and conclusions were made primarily on average women who have survived the first delivery already

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