What Does Delayed Periods, Cramps And Negative Pregnancy Result Indicate?

I just found out i was pregnant 12-22-14 my lat period was 11-22-14.. I was having cramps and using the rest room i didn't know what was going on I took a home pregnacy test but it said negative. I went to the ER i was told I was pregnant but my hormones was low i was wondering if this was normal im kind scared what can i do to rise to my hormones this will be my first child and me and my bf been trying for 4 years.... PLEASE HELP thank you!!!!