Welcome to HCM
I would like to tell you that bleeding from gums occasionally can be due to hard vigorous brushing.
Tooth brush injury can also result in bleeding gums
Secondly it can be due to vitamin C deficiency
.To get rid of this problem you need to take citrous food in your dietary habits like amla, lemon, orange.
Thirdly it can be due to some hormonal changes.
Still you should consult your dentist
& go for complete dental check-up.You might be having caries or abscess in your teeth.
You also try to maintain proper oral hygiene
by regular brushing & interdental flossing.