Hopefully Michelle can dig up that post (I'll leave it up to you, Tai LOL).
I remember there was a lot of useful info in that one...
In the meantime, I know you basically want to look for THE LOWEST HCG detetction you can find. You want the detection numbers to be as low as possible because if you are early in pregnancy, your HCG levels will (obviously) be low. Your HCG doubles every other day in pregnancy so, if you get a - result, skip a day and test again.
If I remember correctly, I've used FR test and they don't print on their packaging what level of HCG they test for.
I've gotten dollar tree tests that test for 20 units of HCG, which is a really good test. And cheap. Most of the cheapie tests are made by the big drug companies anyway, and they all test for the same thing...its just a matter of the LEVEL they test for.
How long have you been TTC?