Am I pregnant?

Over the past week before my period I have been slightly cramping and headache or two some backaches and I started to bleed a bit today but my period hasn’t been a day early in a long time. I’m on birth control and have been for almost a year I don’t use condoms while having sex. Is it likely this is implantation bleeding or probably an early period. I orgasmed yesterday and heard that can kick start it but I dont know..