I recently got off birth control about a month ago and my period is currently ten days late, about 99% sure I’m not pregnant considering ive only had sex once in the past three months and and it was protected entirely. I also went to doctor about a month back and was checked for pregnancy/STDS and was obviously not pregnant. I’m having horrible symptoms though like back pains and tender breasts. Does this mean I could be? Or is there a reason my period is so late.