Hi and welcome to HCM.
This is not serious in most cases and usually is caused by teeth or gingival bleeding.Also it can come from the nose. If you cough
blood then this is something else,it can be sign of lungs damage. Your blood findings may be related to it if you have low trombocytes or clotting factors.Also eosinophlia may suggest allergic rhinits which can cause nose bleeding. You should visit dentist
or ENTif you notice this again. Wish you good health.