Thanks for posting your query.
From the information you have provided,
I understand that both your ovaries and major portion of the uterus
has been removed as a treatment for ovarian tumour. I am not sure why the cervix was left behind as we usually remove the uterus & both ovaries when we are treating a malignant ovarian tumour.
The reasons for pain could be
1. Operation itself- as healing occurs - pain will lessen
2. Infection- in the urine/in the pelvis- which needs tests like urine tests & scan
as a side effect of the pain killers - laxatives to give a complete bowel evacuation will relieve the pain
4. Residual tumour - this is a small possibility
( As you have not mentioned the time lapse since surgery- I am not able to comment on the possibility of residual /recurrent tumour)
5. Very rarely, it can be due to a blood clot in the pelvic veins- which is more common after pelvic surgery for malignancy. This can be picked up by special scans and you will need blood thinning injections to dissolve the clot.
Even if its just the effect of surgery, you need more pain killers after a thorough evaluation as you are not better with what you are already taking.
All the best, Hope I have cleared your doubts!
Please, do not hesitate to contact me for further queries.