Pregnancy is the period that passes from the implantation of the fertilized egg into the uterus until the time of delivery.
Sometimes it is impossible to know the exact moment of the beginning of pregnancy and from there calculate the weeks of pregnancy and the date of delivery, therefore we will tell you how to do the accounts well and be able to organize your pregnancy calendar.
The approximate duration of a pregnancy is 280 days. 40 weeks are calculated from the first day of the last menstruation or 38 weeks (approximately nine months) from the moment the fertilization of the ovum occurs, which in a regular period ovulation usually occurs 14 days after the menstruation occurs .
But how to calculate the time of ovulation is not always feasible, especially if your periods are irregular, pregnancy is counted in weeks. Most women do not know exactly when they ovulate, but they do know when their last period began.
In any case, if you are thinking about getting pregnant, it is important that you write a calendar every month on the first day of each menstrual period, so that you can make a more approximate calculation of the weeks of pregnancy.
When does implantation of the fertilized egg occur?
It is impossible to know the exact moment at which the implantation of the fertilized ovum occurs in the uterus, milestone that begins pregnancy.
But we can approach if we take into account that ovulation occurs in the middle of the menstrual cycle and that fertilization can occur on the same day of ovulation and up to two or three days later.
Six or seven days after the egg is fertilized, the blast begins to produce extensions that will allow it to implant in the endometrium (inner wall of the uterus). In some women, this process results in what is known as implantation bleeding.
Nagele Rule: Know the due date
The Nagele Rule is a simple formula for knowing the probable delivery date (FPP). On the first day of the last menstruation you have to subtract three months and add seven days. The result is the probable date of delivery.
For example, if your last rule was March 1, you have to subtract three months, December, and add seven days: the probable date of delivery is December 8. In the case of a leap year, one day must be added, after any date after February 29.
Here you have a calendar for months and days to calculate the probable date of delivery.
Calculator of pregnancy weeks and due date
So you can calculate exactly the week of pregnancy you are in and the probable date of delivery we have made a very simple to use pregnancy calculator.
You just have to enter the date of the first day of your last menstruation and it will tell you what week you are in, how many you have left and the probable date of delivery.
The trimesters of pregnancy
Finally, as you know, in addition to weeks, pregnancy is divided into three quarters.
- The first trimester of pregnancy ranges from fertilization to the 14th week of pregnancy (12 weeks gestation)
- The second trimester of pregnancy ranges from week 14 to week 28 of pregnancy
- The third trimester of pregnancy ranges from week 28 to week until birth.
To know how your baby grows during pregnancy and the changes that occur in the mother week by week you can check our Pregnancy Calendar.
Photos | Frank de Kleine and surlygirl on Flickr
In Babies and more | What is pregnancy ?, Pregnancy week by week in pictures
