Most test need AT LEAST 20mlu HCG in order to be picked up on a pregnancy test. There is some ancedontal evidence that shows some tests can pick up a pregnancy as early as 7mlu.
There is absolutely no what to know your levels without a blood test BUT you can look at this chart to get the typical range:
Answer by miasmommy21407 at 10:51 PM on Feb. 8, 2011
Answer by Roadfamily6now at 1:06 AM on Feb. 9, 2011