@anonymousconcerns
Small amounts of blood are often not serious but personally I wouldn't assume that. I would want to rule out it being serious. I would go have it checked out and even though they may not have an answer they should know if it's serious or not. I had blood I believe 9 times. 8 times were expected (kidney stone surgeries) once was a kidney infection. Always better to check things out sooner than later.
Best of luck ,
Jake