Should I be worried??

B • married • mommy to be May ‘18. ❤️

Last Thursday (Aug. 31) I had a negative pregnancy test. Tuesday (Sept. 5) I got a positive pregnancy test! So today, (Sept. 9). I went to the hospital because I had some cramping and a few days ago I had some brown spotting. They did an ultrasound and saw nothing, but my HCG is at 130. Should i be worried? Please help.