Pregnancy test won't give me an answer. why?

OMG! I'm going through the same thing.. I had 5 negative urine tests, 1 missed period. then i took a blood test but it was undetermined, so i retook it a couple of days later and i found out today that it's positive, the doctor said it's probably a very early pregnancy but now i have to retake it tomorrow to make sure... it's frustrating not knowing.