Pain on deep penetration or after intercourse is due to pelvic inflammatory disease, endometriosis, irritable bowel syndrome, pelvic tumors, cervical and uterine infections and tumors. Depending on the site of pain during or after penetration, diagnosis can be made. This can be further confirmed by clinical examination, ultrasound abdomen or CT scan, PAP smear and a STD panel as required.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.