Week by Week (First Trimester)

Week One
This week, your last period starts and your uterus sheds its lining. Bleeding happens and the hormones in your body are preparing another egg for release.

Week Two
The uterus lining may thicken now and ovulation is just about to happen.

Week Three
This could be the week you get pregnant! Fertilisation may occur when your partner sperm meets the egg in the Fallopian tube. Fertilisation may take up to four days. When an egg is fertilized, it is called a zygote.

Week Four
Time for the little zygote to find its nesting place in your uterus. By the end of the week, you would have missed a period and this is one of the first sign that you may be pregnant. Some women notice a slight bleeding and mistake it for their period; this is in fact implantation bleeding.

Week Five
Your baby is about the size of an apple seed and is called an embryo at this stage. By this time, he already has a beating heart of his own and the placenta and umbilical cord are full operation. His primary brain vesicles start forming, the nervous system begin to develop and two heart tubes are fused and begin to contract.

Week Six
This is the stage in which you actually start feeling pregnant. Get ready for all the physical sensation associated with being a future mum - sore and tender breasts, nausea and fatigue. If you have visions of a tiny human being growing inside you at this point, be warned that the embryo looks more like a tadpole than a little baby at this stage. Still, its head, tail and arm buds are recognizable and limb buds are already present at this point A very early fomr of a liver pancreas, lungs, thyroid gland and heart appear and blood circulation is well established. The stomach and the primary intestinal loop is also present. Most noticeably, the heart actually bulges from the embryo’s form and the cerebral brain hemispheres are constantly being enlarged.

Week Seven
It’s a busy time for the little embryo - the heart is completely formed, the trunk of its main body gets longer and straighter, the umbilical cord start forming and spleen and liver ducts form. The stomach, kidneys and oesophagus begin to form and in the face, the eyes appear as dark spots, the tongue and eyelids form and the head is relatively larger. In embryo’s brain, the celebral cortex - part of the brain directing motor activity and intellect - can be seen.

Week Eight
The embryo is now half an inch long and the leg and arm buds have divided themselves to form the baby’s thighs, feet, hands, arms and shoulders. Reproductive organs start to form and so do the cartilage and bone. The head is now in a more erect position and its neck is more developed. The external ear is now well formed and the eyes develop pigment. In the brain, nerve fibers connect the olfactory lobe.

Week Nine
The first foetal movements can be detected on an ultrasound, so watch carefully this week! The abdomen and chest cavities have separated by this stage and eye muscles and upper lips are developed.

Week Ten
The embryo is now one and a quarter inches from the top of the head to the rump. Bones are replacing cartilage, the stomach moves to its final position and the diaphragm separates the heart and lungs from the stomach. Neck muscles also form at this time.

Week Eleven
The head is half the size of the actual foetus right now. Eyelids have fused shut and will stay this way until week 24. external sex organs are forming now, so are the hair follicies and teeth.

Week Twelve
A skeleton of cartilage is forming and the lungs are completely formed, along with the thyroid gland and pancreas. Baby’s liver functions to make blood cells now.

Week Thirteen
The foetus is now three inches long, with the trachea, lungs, stomach, liver, pancreas and intestines developing into their final functions and forms. Vocal cords begin formation, while tooth buds appear for the 20 baby teeth. This is the time when finger and footprints, and fingernails, start to appear.

Week Fourteen
Ears are now moving from the neck onto the head. By this time, baby’s sex organs have fully differentiated themselves and are clearly male or female.