Janet is extremely concerned and anxious about getting sick….

Janet is extremely concerned and anxious about getting sick.  She spends an hour each morning and each evening checking her body for any signs that she might be sick.  She has already gone to the doctor four times in the last two weeks, despite not actually having experienced any physical symptoms.  Her visits to the doctor have consistently shown that Janet is physically just fine and that there are no signs of her being sick.  What Psychological Disorder does Janet likely have?