low levels at 6 weeks 5 days

Li

I just suffered from a miscarriage on June 25th. i was almost 6 weeks and my levels were only at a 9.... I'm currently 6 weeks 5 days pregnant and I think it's happening again. the first time I had light brown spotting and I thought it was implantation bleeding but I was obviously wrong the same thing is happening again now and I went to the ER and my levels are only at 2500. the doctor said that they should be a lot higher the spotting is continuing it is light brown and did get heavier last night but seems to have slowed down again.I have to get my levels checked in another twenty-four hours and I'm trying to get an ultrasound today I am just terrified that I am going to lose my baby. has anyone had levels this low at 6-7 weeks similar situation and had a healthy baby??