Gum disease and ......

If it continues to be a problem, go see a dentist and find if there is any local problem, such as gum inflammation and etc. If there is no local problem and you continue bleeding, you are going to open a big can of worm for diagnosis workup, ie., you have to rule out systemic diseases:

Thrombocytopenia (ITP), coagulation issue, vitamin C deficiency and etc...

Blood works to be done initially: CBC with diff, CMP, PT/INR, APTT. Further blood work may be needed.

Good luck!