My wbc was 15, is that dangerously high?

No.: Suggests you are fighting an infection, but could be from steroids, stress or other things. Must be considered as one piece of the whole picture, not in isolation.

Mild elevation: Can be from an infection viral or bacterial.

White count: Although white blood cell count has meaning it in itself does not mean you have dangerous symptoms. For example 20 percent of people with appendicitis have a normal white count. A white count of 15, 000 is elevated and ususally consistent with an infection, but not necessarily critical.

Depends: It all depends on what is causing it. A WBC this high is not unusual in many common bacterial or viral infections. But if this is a persistent observation, then it can be problematic.