When a woman is 4 weeks pregnant, it actually means she conceived two weeks earlier.
The reason why it is referred to as her fourth week of pregnancy and not her second is because doctors start counting your pregnancy from the first day of your last menstrual period.
During the first two weeks of pregnancy you have not even conceived.
The first two weeks occur while you are having your menstrual period and up to ovulation.
After ovulation, conception occurs and this is when your pregnancy actually begins, but for the purpose of dating pregnancy the count starts at the start of your last menstrual period.
During your fourth week of pregnancy, the week that you should be able to test positive on a pregnancy test, a lot of things are happening.
Your baby looks like a tadpole at this point and is only about a millimeter long.
You may have started to notice pregnancy symptoms already, but it is likely that the classic pregnancy symptoms like morning sickness and cravings haven't started yet.
You would have expected to have a period this week and when it doesn't arrive, this may be when you might start to think that you are pregnant.
A missed period is one of the first signs of pregnancy.
At this stage of your pregnancy, you may not notice a whole lot of changes.
You may even feel like your period is just about to start.
Early pregnancy symptoms often feel very similar to PMS.
You may feel bloated, moody, have breast tenderness, or have skin breakouts.
Menstrual like cramps are also common.
As the weeks go by you will start to notice more changes and feel more pregnant.