What Causes Unexplained Bruising On Thighs?

I have unexplained bruising on both thighs that has been continuous for almost a year. The bruises have faded but do not disappear. Some of the bruises started with a small tender bump under the skin. Also my platelets are low, not much below normal range and my family has a history of auto immune. From my blood work my doctor suggested that I see a hematologist but there is not one within a 100+ mile radius of where I live. Please tell me what concerns I should have and what are the possibilities that I should be screened for.