Accurate?

horsevaulter

How accurate are blood test screenings in being able to tell how far along you are? The Dr told me they test for the amouont of a hormone present and can tell that way. I drank 8 glasses of water before my appointment (maybe I shouldn't have done that but I have been sooooo crazy thirsty lately! ) Anyways they told me that I am only 4 weeks and 3 days PG. I found out last week that I was pregnant.. Is it even possible to get a positive test at 3 weeks? And I am already feeling quite a few symptoms...

Thanks for your feedback!