Im not a doctor but it could be anything from brushing your teeth to cancer esample: injury inside the mouth or nose or something going on in your tummyor even drugs I would personally seek perfessional help! I don't know if this helps
gums or small nose bleed.
you could have a gum deisease called gingevities. ask your dentist to perscribe you some medicated mouthwash and use it twice a day.