Bleeding in between periods - it all started when I recently started to masturbate with a toothbrush

I recently started masturbating with the end of a toothbrush (i feel so embarrassed admitting this, but I saw that other girls had done it) anyway, so now I have started bleeding in between my period, and I am really scared. I read that I may have hit the cervix, or gone too deep/hard? Please help, I am too scared to talk to my mum about it or go to the doctor.