BFP but hcg level is 6.

No doctor has been able to explain what happened to me. And I’m really hoping that someone here has some experience in this field. Two weeks ago I started a little bleeding that got a lot heavier and darker towards the middle and then became light again. The bleeding is still happening today, two weeks later but it’s gotten a lot lighter. On day 10 of the bleeding I took a pregnancy test because I had a feeling that it wasn’t my period, I took the digital clear blue test and it came back positive. So I went to the Er and they said they couldn’t see anything in the ultrasound and that my hcg level is 6. They didn’t say that it was impossible for a pregnancy test to come back positive at an hcg level 6 but my Ob insisted that there has to be something wrong with that test and that there is no way that at a level 6 the test can come back positive. So I bough a new package and tested again and it was still positive, only now my hcg level is at a 4. I’m extremely confused and my doctors, physical, Er doctor, and ob all said they had no answer for me. My ultrasound shows nothing, everything looks fine. My hcg is getting lower. I didn’t have clots in my bleeding, it was like a normal period bleeding. I got some period cramps on days 4,-6 and then I felt nothing until day 12. That’s when my horrible right side pain and pelvic pain started. It’s the worst pain I’ve ever experienced and I have experience a lot of pain. I just want to know if it was a miscarriage or something else. I was told that it would be hard for me to get pregnant naturally so though I would still be so heartbroken but I would have some relief knowing it was a pregnancy because I was basically told it won’t happen.

I’m sorry I know this post is too long. I hope someone can help.

I apologize for the blurry picture. I was shaking like crazy.