The first month of the gestational calendar begins at week four of the pregnancy. By this time, you've already missed your menstrual period and you've probably confirmed your pregnancy with a home urine test or with a blood test taken by your practitioner.
Everything may appear not to have changed much, but in this first stage your emotions will be the first thing to resent. From now on until the end of your pregnancy you will change physically and emotionally and you'll experience feelings like excitement, anxiety, happiness, ambivalence or joy. All this are normal, and you don't have to worry, you're becoming a mom and this are all part of this process.
Some aspects of pregnancy are predictable but others my vary. You can not compare your pregnancy to others. Some women, for instance, experience fatigue or nausea while others find out that the world is more beautiful, so you may conclude that some women feel delighted and other challenged by pregnancy. At this time a tiny being is growing inside of your body, so it's important that you understand what is going on with your body.
Keep always in mind that emotional variations are normal, they may happen during the pregnancy and you can not compare your state of mind with other women.

The Baby // Developments
Do you remember what you've learned in school about conception? How it occurs?
If you don't remember here is a linearly what happens. One or more eggs is released by the woman's ovaries and travels down through one of the fallopian tubes. When the man ejaculates, semen is deposited into the woman's vagina. Within the semen are millions of sperm that travel into and through the woman cervix, continuing thought the uterus and up the fallopian tube to the egg. When the sperm penetrates the egg, they unite and within hours, the fertilized egg cell begins to divide. Then, the fertilized egg travels from the fallopian tube into the uterus and in a few days it will attach itself to the wall of the uterus and the placenta will begin to form.
At the forth week your baby will be approximately 1/4 inch long, about the size of a pea, and at this stage is still called an embryo. The neural tube forms between week four and six, and this it will develop into the baby's brain and spiral cord. Other organs will develop rapidly too and by the sixth week you may be able to see them using an ultrasound machine that is equipped with an amplifier and that will allow you to ear your baby's heartbeat for the first time.

Your body // Pregnancy tests
First you must make a pregnancy test. Home pregnancy tests are quite accurate. The tests detect in your urine the pregnancy hormone hCG (Human Chorionic Gonadotropin) which is produced by the placenta and released into your blood stream. Home pregnancy tests are quantitative and to show you a positive result there must be a certain minimum amount of HCG in your urine. An early pregnancy test may show a negative result even though women are pregnant. So, if your period hasn't started two weeks after the test is important that you repeat it.
You may so take a blood pregnancy test. This test is quantitative and more accurate and it can show a positive result 14 days after the conception..