Hcg levels 20,000 at 6weeks but they can’t really see a fetus

Maria • I

I went to ER last night because of some dark brown discharge, I had an ectopic in May so I am very concerned. They checked my hcg levels and are 20,000 but on the ultrasound they couldn’t see the fetus they only see something inside the uterus but they cannot say is a fetus I am only 6 weeks pregnant I know sometimes you can’t really see anything but I hear that with high hcg levels is more probable to see the fetus anybody here had same problem?