Does a woman always have an hcg level even when shes not pregnant? for example: my friend had a urine and blood test done, her blood test showed 1ml of hcg but they told her she was not pregnant. then in december she had .6 but not pregnant.

Yes. It's a test.: An HCG level is a blood or urine test. If such a test is done, a result will come back. Therefore, there is always a result, a level. The level may be zero or may be something "less than" the minimum confidently detectable level the lab can produce. That's why results are just numbers and have little or no meaning unless interpreted by somebody who knows the reason behind the test.