Hello,
Thank you for posting your question to HCM.
I understand very well your concern.
Canesten is a very safe medicine in general and the side effect that you have is very doubtful to be from canasten. It may give some irritation or
redness if used for longer than needed, not not bleeding.
Birth control pills on the other side cause a lot of changes in the period, and it is normal.
So my thoughts would be that the blood is either...
..from the birth control pills- you don't have to worry about it, it will compensate next month
..or from the rectal area- check if there is any sign of hemorrhoids or skin damage around there.
If it continues, gets more profuse, other symptoms start, then I would consider a visit to the gynecologist. It doesn't look worrisome from what you are describing.
Hope this helps,
Let me know if you have any other question.
Take care.