Week 3 of Pregnancy - FamilyEducation

Week 3 of Pregnancy

First Trimester

Your 3rd Week

This is the week a miracle takes place--your baby is conceived.
Fertilization of female egg
Fertilization
4. Cells surrounding the egg secrete chemicals that aid egg development.
3. The whiplike tail of the sperm propels it up the fallopian tube to meet the egg.
2. The sperm's head carries genetic material along with enzymes that enable the sperm to penetrate the egg's tough outer layer.
1. Egg
5. Fluid-filled cavity
6. Blastocyst
7. Lining of uterus
8. Cell cluster within the blastocyst's fluid-filled cavity forms the beginnings of the embryo.
9. The outer cells of the blastocyst anchor into the lining of the uterus.
10. Maternal blood vessels
Cells surrounding the egg secrete chemicals that aid egg development.The whiplike tail of the sperm propels it up the fallopian tube to meet the egg.The sperm's head carries genetic material along with enzymes that enable the sperm to penetrate the egg's tough outer layer.EggFluid-filled cavityBlastocystLining of uterusCell cluster within the blastocyst's fluid-filled cavity forms the beginning of the embryo.The outer cells of the blastocyst anchor into the lining of the uterus.Maternal blood vessels
If you ovulated and the egg met a sperm, amazing things will happen fast. It takes just three days from fertilization for a single egg to divide into a ball of 58 cells. By the end of the week, this ball, called the blastocyst, will have reached the uterus, where it will start to implant in the lining. It will be a couple of weeks before you know whether you've conceived, but special hormones kick in now to help maintain the pregnancy.

You are 2 Weeks and 2 Days Pregnant

What's happening insideHere a human egg cell 24 hours after fertilization is artificially colored purple. Around the egg is a thick layer (yellow) that has now become impenetrable. The two red areas, or pro-nuclei, contain genetic material from the mother and father before it has fused. read more

You are 2 Weeks and 3 Days Pregnant

What's happening insideWhen the two nuclei have pooled their genetic material to create a cell containing its full complement of 46 chromosomes-23 each from the mother and father-the cell can start dividing, shown here at the first division creating a two-celled body. read more

You are 2 Weeks and 4 Days Pregnant

What's happening insideThis is an embryo at the 16-cell stage, when it has changed from a zygote into a morula. It is in the process of dividing into a hollow ball of cells-the blastocyst-which will eventually implant in the lining of the uterus. read more

You are 2 Weeks and 5 Days Pregnant

What's happening insideThis is an embryo at the blastocyst stage, five days after fertilization. It is seen hatching from the shell that originally surrounded the unfertilized egg. At this stage, the blastocyst has moved into the uterus and is preparing to implant. read more

You are 2 Weeks and 6 Days Pregnant

What's happening insideThe blastocyst prepares to embed itself in the lining of the uterus-the endometrium. Once it is completely implanted-usually around seven days after fertilization-the pregnancy will become established. read more

You are 3 Weeks Exactly Pregnant

What's happening insideThe blastocyst is firmly embedded in the lining of the uterus. Once this has happened, the placenta (the temporary organ that supplies the growing embryo with oxygen and nutrients) will begin to develop. read more

You are: 2 Weeks and 1 Day

What's happening insideHere the egg is shown surrounded by sperm. Although only one sperm will fertilize the egg, several hundred are thought to be necessary to break down its defensive layers and enable fertilization to take place. read more