Question...

I missed my period and took a pregnancy test. I was super happy to see it was positive! This was Thursday morning. This morning I started bleeding and cramping so I went straight to the ER. I have had 3 miscarriages so I know the drill....when I got there they did a blood test that revealed no sign of pregnancy!? Has anyone else had this happen!? I’m still cramping and bleeding and it’s not like a period. I’m so confused :(