please help

7 weeks and 3 days today. started bleeding on monday, the 18th, heavily. got an ultrasound, nothing showed up no sac or anything. got my hcg tested and the numbers are still rising, not doubling, but went from 1100 to 1400 in 48 hours. yesterday i bled so heavy and had such horrible pain and was passing clots, was positive i had miscarried. got an ultrasound done today, again didn’t show anything in my uterus. dr is concerned of ectopic, is having me get hcg tested again tomorrow. the bleeding went from heavier than a period with clots yesterday to spotting today. anybody have any idea? anybody gone through this?