Your pregnancy: week 4
In week 4 of your pregnancy, a blastocyst embeds itself into the uterine wall. This process is called implantation.
It divides into two parts: the half attached to the uterine wall becomes the placenta, which will provide nourishment to the baby. The other half becomes the baby. The amniotic fluid (which will protect the embryo) begins to collect. The umbilical cord, which will contain two foetal arteries and one foetal vein, also starts to develop.
Cells on the back of the embryo fold in the middle to form a tube. This will become the spinal cord. The brain’s major sections form at the one end.
What is happening to you
Some women experience slight bleeding (implantation bleeding) at this time. Implantation bleeding is lighter than a normal period and is pink or brown in colour. It may be accompanied by cramping. In the case of unsuccessful implantation, a woman may experience a heavy period, somewhat later than usual.
What to do
Do a home pregnancy test. If you test positive, make an appointment with your doctor. Ask about nutrition and an ante-natal supplement. If you’re taking any medication, discuss this with your doctor as your treatment may need to be altered. Your doctor will do “booking bloods” to determine your blood group and to test for syphilis, immunity to rubella, Hepatitis B, HIV, haemoglobin, signs of infection and protein in the urine. A “Pap” smear of the mouth of the womb may also be performed.