Anything above 5 is considered pregnant. You're still only 6DPO, which si still really early anyway. I would go in a few days and have the blood work repeated, and if that number had risen then you're pregnant, if not, then you're most likely not pregnant.
When I had a miscarriage back in April. My HCG was at a 4 when checking for completed miscarriage which is considered not pregnant. I have heard anything under 5 is not pregnant and anything 5+ is
I agree with the post above, I would have blood drawn in a few days to see if numbers go up and then go from there.
I have heard several different things. Some people say anything above a 5 is positive and some say 8, I have never heard 3 tho.... I would just have by blood drawn again in a couple days to see if the numbers have gone up! Good Luck