What causes petechiae and splinter hemorrhages with normal blood test?

I am a 29 year old male. Have had petechiae and splinter hemorrhages for 3 months. The petechiae are mainly on my arms. Also have multiple splinter hemorrhages most of the time. Right now I have three on my left thumb, one on my right pointer finger, and one on my right middle finger. I showed them to the hematologist and he said they didn't look like emboli. The blood test I have had done are cbc, esr, liver enzymes, heart enzymes, blood culture, and a workup for lupus. With the only abnormalities being a high wbc at 11.7 but normal differential and low platelets at 138. Other test I have had ran are chest xray, ekg, 2d heart echo, and 24 hour urine. All of these were normal. The only other thing I have noticed is my fingernails have heavy ridges and dents in them. Have never ran a fever or anything like that. So my question is does this sound like anything anyone has heard of and should I be so concerned about it?