HCG blood test level says I'm pregnant?

Hi everyone! Ok so...I happened to be at the hospital on Friday night and they wanted to run tests but asked me if I could be pregnant. My fiance and I told the doctor we are trying to conceive so he ordered a urine test. I showed him a calendar and when my last period was and when I ovulated and he saw that on Friday I was 8 or 9 DPO so he ordered a blood test as well because the urine test prob would see it that early. So the urine test came back negative (which I knew it would). But the blood test came back and my HCG was 8. The doctor said it shouldn't be anything higher than 2 before he sent the blood away. However I ended up being discharged by the nurse and not needing the tests afterall and never saw that doctor again. So I never got the chance to ask him if my HCG was up at 8 than doesn't that mean I am pregnant? (I read that anything over 5 means yes) Has this happened to anyone else? Also...If my HCG was 8 on Friday and it will be 72 hours after that test by tomorrow morning...is it too soon to use an early detection pregnancy tests that picks up HCG when it is at 20? What would my HCG be (typically) tomorrow morning? Any personal or professional advice or info is welcome...HELP !!!! Thanks all !