I Have Been With The Same Partner For A While

I have been with the same partner for a while and have only just started bleeding when it is clitorus stimulated. There's in no pain and I only bleed when I climax. I was assuming it was just old blood because I no longer get my periods because I am on the Depo. I don't bleed when we have intercourse though. Is this normal or should I seek advice from a doctor?