negative blood test, but still have pregnancy symptoms

Hi my name is dessie. And i believe i am pregnant.I done had 3 urine and 1 blood test done they all done came back negative. But I don't know cuz i still have pregnancy sypmtoms and my stomach is growin a little.I went to the hosptial to get a ultrasound done,but they denied me.Saying that it was a tumor in my breast thats makin my feel like this,but I think it not.So what should i do,wait till they take the tumor out or before they take it out to see?[/b]