Take a look at each week of your pregnancy, from conception to birth, with our comprehensive email newsletters.
Congratulations, you are now officially pregnant. Being 3 weeks pregnant means that one of your partner’s sperm and one of your eggs have combined and you are in the earliest of stages of pregnancy. If, by chance, you have released two eggs and they have both been fertilised, you will be pregnant with non-identical twins. You won’t know it though; all of this activity is going on deep within one of your fallopian tubes at a tiny, microscopic level. At 3 weeks pregnant, you are still a few weeks away from starting to feel the effects which pregnancy hormones will be going to have on your body.
The process of fusion between your egg and a single sperm takes around 24 hours. Only one sperm makes it through to the centre of the egg, although a lot battle it out to be the one and only. At the moment when one sperm is successful, the egg builds up a protective wall around itself to stop others from entering. Eventually, the other sperm give up trying. If one egg is fertilised by a single sperm and divides separately, identical twins are formed at this very early stage.
The newly fertilised egg is now officially called a zygote and it starts dividing into more and more cells, until around the 3rd day, when what was originally 2 cells, have now become 12. The zygote is still in the fallopian tube at this stage, though it is steadily finding its way down to the uterus where it will stay, hopefully for another 37 weeks or so. Little finger like projections of hair called cilia, line the fallopian tube and wave the zygote along to discourage it from settling in where it shouldn’t. It takes around 60 hours for the fertilised egg to weave its way down to the uterus, by which stage there are 60 cells, all with a predetermined job and a specialised function. The outer cells will form the placenta; the inner cells will form the baby.
Around a week after the egg has been fertilised in the fallopian tube, it embeds in the lining of the uterus. By now, there are 100 cells bunched together and it is called a blastocyst. At this early point, the pregnancy hormone Human Chorionic Gonadotrophin (HCG) is produced and it is this hormone which can be detected in your urine or blood when a pregnancy test is done. If the signals to keep producing HCG aren’t received, the lining of the uterus isn’t needed and is shed in your next period.
Now, let’s see what happens in week 4 when implantation of the fertilised egg occurs.
Always consult your physician before beginning any exercise program. To reduce the risk of injury, never force or strain yourself during exercise. If you feel pain, stop and seek medical attention if necessary.
These programs have been created by Katie Brown - yoga teacher and infant massage specialist
Your baby’s due date: March 13 - March 25, 2021
Baby’s star sign: Pisces
Chinese year: Ox
Famous people born around your baby's birth date: