Been on depo-provera for 8 yrs last shot was in july just started having severe cramping and pain in left ovary and very tender and sore breast not pregnant?

Ovulation: if your last shot was in July, then its effects have likely worn awayand you are certainly at risk of pregnancy, so I would get tested first. If you are not pregnant then this pain that you are feeling could be related to ovulation. It's unclear to me if you have a ruptured cyst or a cyst that is twisted. Seeing a gynecologist and getting an exam and an ultrasound would help.