Thanks for writing to us.
There are two possibilities
1) Small furuncle
which has burst open and draining blood but this is usually mixed with pus and self limiting (unlikely recurrent)
2) Fistula in ano or pilonidal sinus
both of which present with recurrent bleeding or pus discharge
As per your history, the first one is more likely
In either case, I dont think we need to worry at this stage if you do not have fever
and if this problem does not occur repeatedly (apart from the episode where you mentioned that you wiped off a little blood).
Hope this answers your query.
Please do let me know if you have any further questions.
Wish you a speedy recovery.