At the beginning of this week you would normally start your period. If this does not occur it may be possible that you are pregnant. If a fertilised egg has now embedded itself in your uterus, the flood of hormones through your body will cause your menstruation to stop.
A pregnancy test around this time will be able to detect the hCG hormone, also known as the pregnancy hormone, in your urine. Every two days the amount of hCg doubles so if you produce a negative test one day it may be that the levels of hCG are too low to be detected and you should wait a few days then try again. Around weeks seven to twelve the levels of Hcg in your blood will reach their peak before they begin to lessen, increasing again towards the end of your pregnancy.
It may be that you do not require a test to be sure about your pregnancy. At this time you may begin to suffer from fatigue or nausea, especially in the morning. You may also notice a change in your breasts and feel the need to urinate more frequently.
The fertilised egg is now beginning to take shape and cotyledons begin to form. These cells provide the basic building materials for the organs of your baby. The embryo sits within a cavity filled with amniotic fluid, contained by a membrane known as the `amnion`. This in turn is enclosed by another membrane called the `chorion`. On the ouside of the chorion are adhesive cells which glue the egg to the uterus wall.
The outer layer of the embryo is covered in small groups of cells which will eventually become the placenta and umbilical cord. The placenta allows nutrients to pass through your blood and into the baby's blood stream with all waste being discharged back into your body for secretion.
The embryo is now changing its shape from a ball to an oval with the back wider than the front. In the middle is now a cleft containing the neural tube. It is here that the nervous system will be housed. On both sides sit small protrusions which within a few weeks, will take shape as the bones, ribs and muscles.
Your body is now beginning to work harder to ensure the safety of your baby and the mucus plug protects it from outside dangers.