What's wrong with me?

Pa
Ok so I been cramping really bad the last couple days I'm 9 days late which is rare but I took 3 test and came back negative. Then I went to hospital because of cramping they did a blood sample not pregnant. So where is my period and why do I have the worst pain ever?? It literally feels like how u feel after having a baby the pain and burning and abdominal cramping plus lower sharp shooting back pains. I feel like I'm dying...anyone else experience something like this?