Help! HCG is "high", NOT pregnant

33F. My period was 4 days late on Thursday. I'm a type 1 diabetic (diagnosed 6 months ago). My endocrinologist ordered some blood work and my HCG came back high at 5, but I'm not pregnant. All other hormone levels were normal. I got my period Thursday evening, about 5 hours after the blood work was drawn. She is sending me for another blood draw to re-check my HCG but what would cause a high level? Is a high level of 5 something to be worried about?