Is a white blood count of 12.7 a bad thing?

No it's likely fine: Your WBC (white blood count) varies from day to day and can go up and down for a variety of reasons. In pregnancy for example, women will often times have a WBC in the range of 15. Also, 12.7 actually is 12, 700. However, alot of it depends on what your current health condition is and in general a 12.7 by itself is likely ok.

Depends: Why was the test done? Do you have any symptoms? All laboratory results need to be interpreted in the clinical context and the doctor who ordered the tests is usually in the best position to do that. Talk to the doctor who ordered the tests. Having said that, this may be your normal.

Leukocytosis: If you're not in the middle of some obviius inflammatory disorder, a total white blood cell count of 12,500 could be a red flag for a bone marrow disorder or an occult infection. At the very least, a repeat complete blood count and differential cell count should be done. Discuss this with your physician or a hematologist.