Is Bleeding From Nose Post Head Injury A Cause For Concern?
Probably not.
Detailed Answer:
I read your question carefully and I understand your concern.
In itself that blood running from your nose shouldn't be a matter for concern. It may be a ruptured blood vessel due to the hit, which is still fragile and bleeds. So if no other symptoms it wouldn't be a cause for concern.
It might require more attention though if you start to develop increasing headache or fever which may indicate a sinus infection favored by presence of blood in your sinuses.
An alarming feature would be if there was clear liquid running from your nose which could be cerebrospinal fluid. However I doubt that will be the case as it happens when there is serious trauma with skull fracture and usually there are other signs.
I remain at your disposal for other questions.