Hi I Only Did Clitoral Stimulation With A Vibrator A

Hi I only did clitoral stimulation with a vibrator a day/two days later I started bleeding. I didn't insert anything. I am currently on the Cerazette pill, I used to be on Microgynon (and, it never happened when I was on Microgynon). I haven't had a period for a good few months say approx 8-9 months, I think though that I had a withdrawal bleed though at approx September 2015 (can't find my chart). Anyway, my question is this...is this normal?