So you think you are 3 weeks pregnant
This is an exciting week because by the end of it you might finally be able to tell if you are indeed pregnant or if there are other factors influencing your periods.
Although at this point you should be able to use a pregnancy test to confirm whether you are pregnant or not, this early on some tests can still result in a false negative. Most pregnancy tests are developed to recognise the pregnancy hormone or human chorionic gonadotropin (hCG) which is produced around six days after a fertilised egg embeds itself in the uterus. At first the levels of hGC are small and can be hard to detect. Waiting another week or 2 might give a more reliable result.
If your pregnancy test is positive it is important that you get this confirmed by your doctor who can also advise you on how to proceed and what happens next.
What's happening with mum
Most of the symptoms associated with pregnancy are as a result of the changes in hormones, especially hGC. As levels at this time are still relatively small you might not feel any different. On the other hand, you may have light cramps, sensitive breasts or symptoms you would normally associate with pre-menstruation. Some women also complain of nausea or loss of appetite at this stage which can be attributed to increases in hormones. This can cause over stimulation of the senses, especially smell and taste, making even the most pleasant of scents eem overpowering or your once favourite sweet seem sickening.
What's happening with baby
I know it might not look like much is happening right now but there are major changes taking place. The ball of cells which began life as a sperm and an egg is now called a blastocyte.
The 23 sets of chromosomes are already deciding the color of hair and eyes your baby will have as well as other genetic factors. The sex of the baby has also been decided from conception and is dependant on the chromosome contained in the sperm. If it was an X the baby will be female, if it is a Y, the baby will be male.
Consider taking another test to confirm pregnancy and perhaps make an appointment with your doctor or midwife.
From angelababy In Q&A