Since you are this early in your pregnancy its not uncommon to get a negative when your not using first morning urine. The blood test is 100% accurate anyways so listen to that.
I had a slightly positive line on tuesday and the doctor confirmed it with a blood test that was only at 7 hcg. Then today i had another blood test but i don't know the results. I didn't use first morning urine but i got a negative hpt on a dollar store test. (which is what i used the first time) any similar stories?
Just like the first answerer said, the tests usually only pick up 25 HCG at the least. That's even the early ones i think. anywhere from 0-5 is usually "not pregnant", so you are just barely above the pregnancy threshold!