I Had What Looked Like A Splinter Under. Y My

I had what looked like a splinter under. Y My thumb nail. It turned out not to be a splinter but blood.so my doctor ordered a blood test. And I'm going to have an echo cardiogram said. Can be a. Signal of possibly an auto immune disease. Or a vascular problem
Didn't get a chance to ask the doctor what the tests are to rule out YYYY@YYYY