Hey AA, I am not a DR/nurse but from experience from getting blood and pee tests even at 28 I can say that sometimes the body just simply does stuff. I have had blood in my urine samples that Drs were not worried over that resulted in nothing. I had mono in the past so I have crazy antibodies all the time in my system (it's a forever kind of relationship lol) if the Dr is not concerned, I would not worry. If you were at like 20000 then I would start asking questions lol but you're not that far out of normal range. Hopefully you'll get the answers you seek next week at your next blood drawing!