Positive Home Pregnancy Test, Negative Blood Test: What Does It Mean?

Question
20, no kids, august 31 2005
Hello it is me again about 3 postive home pregnancy tests and a neg. blood test. You said a sonogram wouldn't show anything until about 6 weeks. according to my doctor I was 6 weeks last week. would a postive blood test show by now. Is this problem seen often? Or am I just rare? I am just really worried.  

Answer
A pregnancy test should show a positive result within 14-21 days after conception. The best time to take a pregnancy test is seven days after missing your period. A blood test for pregnancy may show a positive result 10 days after conception. If you are 6 weeks from your last period, a pregnancy test should be accurate by now. In addition, a sonogram after 6 weeks should show a fetus and a fetal heartbeat. If you are only 5-6 weeks pregnant, it will only show an empty gestational sac until 6 weeks gestational age.If, afteer 6 weeks, there is no elevation or doubling of HCG values every 48 hours, it indicates a non-viable pregnancy.