With my first I didn't know until I was 5 weeks and I had no sympotms apart from the usual tiredness, until 6 1/2 weeks then the nausea hit...not vomitting though. But mostly you don't feel pregnant until you hear the heartbeat (between 10-14 weeks) or unless you have to go for a dating scan.
With my 2nd I knew just before 4 weeks when I got the Nauseas feeling again. That was because I knew what to expect from the 1st time.
Now with number 3 I'm 39 weeks and still have days where I don't feel prgnant...LOL except when I look down or get massive kicks from inside.
Anyway everyone feels like this when they first get pregnant...those 2 blue lines, or the positve blood test are usually all we have to go on until we start hearing the heartbeat.....but don't worry soon you will start noticing changes in your body.
Good Luck and Congratulations, pregnancy is such a wonderful experience.
Mel, SA, Jayden 10/02, Harley 08/04, Zoe 09/06