Hello,
Usually pain during the initial stages of penetration is due to UTI and vaginal infection or vaginitis, a tight vaginal wall, sores at the mouth of vagina or vestibulitis, vulvodynia or a dry vagina (frictional injury), thrush or fungal infection. Pain on deep penetration 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 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.
it can be guilt or lack of foreplay and fantasy. it can also be lack of intimacy between partners.