2 negative prego test still feel pregnant

Hi,
This is the first time I have posted here.
I am so tired and just drained and cant think of being prego anymore.
So, I went to the doctor yesterday because since Sept. 2007 I have been having pregnancy symptoms and I have had 2 negative test results in the doctor's office. My doctor did all these tests too see what it could be and everything came out really good she said. No negative nothing throyid and everthing blood sugar. Anyway, I have sore boobs stretch marks on them red and purple buy stomach is much bigger round like a little ball.
The doctor said that its all hormonal even though my tests came out balanced. I don't understand.
She basically told me just to wait it out. This is the 3rd month I am feeling like this and I am getting bigger around my stomach. pants aren't fitting or anything. I don't know what to do anymore. She said that I can't do anything but exercise and have a balanced diet. Even though I weight 238lbs which I want to loose but at the moment I seem to be gaining for some reason even though I haven't been eating any differently.
Pleas help.
So I what to know if anyone is going through the same thing? Did they eventually figure out that they were in fact pregnant? WHen will I find out.