Need help!

Amy

I am 5w 5d pregnant, I had blood eork done on the 12th and hgc level was 397, the dr said it was low and to have another blood test done on the 14th, hgc was 481, dr said I will more than likely miscarry. I was spotting brown blood on the 14th but only for a couple of hours and then went away until today, spotting red blood this morning but then stopped. Has anyone else hgc went up but not double and go on with healthy pregnancy? I am super scared.