It's called Phantom Uterus. Much like when someone loses a limb but still feels the pain like it's still there. I still experience monthly cycle, it feels like I still have my period even though I no longer have the parts it take.
Chronic Pelvic Pain Syndrome could be caused by a lesion(s) on a nerve or multiple nerves in the pelvic area, such as the sciatic nerve, the pudendal nerve or the sacral roots. Symptoms often include lower abdomen pain, nausea, vomiting and intestinal pain. This pain is usually caused by adhesions, post-operative scarring (especially after abdominal incision) and uterine or ovarian inflammations. Causes include Endometriosis or any type of surgery that involves the ligaments surrounding the cervix (hysterectomy, etc.) Hysterectomy can be followed by pain as though the uterus were still present. Additional surgery aimed at relieving pain often doesn't work and may even make the symptoms worse.