Odd menstrual cycles

I’ve been so confused for so many years. I used to take birth control as a teenager for a short time. Ever since then I’ve never been. My periods are extremely irregular to the point I won’t have a period for months. While I’m not bleeding though I am still getting the brutal cramping and god awful lower back pain. Now today I see that I have spotting even though my period ended a week ago. Does anyone else have any of these issues?