I had 3 positive preg. tests before my period unexpectedly started. i scheduled a blood test and then my period unexpectedly started. i took another test and it was pos. 2 days later @ doc urine sample was negative, blood hgc was 13. what happened?

Based on that blood value,you may have had an extremely early miscarriage. It is difficult to say definitively and generally we recommend a repeat blood test in a couple of weeks to make sure that level is going down to zero

Pregnancy requires a late or missed period. I sounds like you were imdeed pregnant and the suffered a spontaneous abortion, which is known to occur up to 25% of the time. If attempting pregnancy, I would advise having one normal period first. If "miscarriage" occurs again, I would see a trusted board-certified ob-gyn before trying a third time. Good luck!