Hi Munchkin, well I can't be sure but as far as I know even a very faint line is considered to be a positive result. I had the same problem with my test the other day, the positive line was so faint I could hardly even see it, so I called the test company and asked if you would be able to tell by a VERY faint line where the positive line would appear if you were
pregnant and they said no, if you can see a line in the positive window you are probably pregnant. The HCG levels for me would've been a bit too low to be sure though as it was only 5 days after the 'hopeful conception'. Anyway I am testing again tomorrow with my fingers crossed for a clear positive. Good luck to you too, and keep us posted.