Help!!!

Has anyone ever got a positive blood test one day and 2 days later get a negative blood test and be told that you were never pregnant to begin with and that all 4 urine tests were also wrong ? Is it possible to miscarry within 2 days? 2 days after my pos blood test I started bleeding. They also informed me that I have a very tilted uterus. I just had another blood test done today and it came back neg as well. Could they be wrong? I still have alot of pregnancy symptoms tho? Confused.