someone help me understand?????????

AF was due 3.17 I took multiple urine test and they all came back with a vfl. Started bleeding with minor cramps on 3.20.17   Later went to the hospital. Took a urine and it was a vfl also took at blood test and it came back positive .💕 Was told my Hcg level was at 13 and to see my OBGYN within 48-72 hours to retest . Called and got the results and they told me my blood test was negative. 😢😢😢😢