I have been experiencing pelvic pain mainly on the left buttock and coccyx during periods. I feel as if something is pressing down on my bowel and find it hard to pass water and move my bowels during this time. Feel like I am in labour. Been for MRI which was normal, ultrasound and laparoscopy again with no issues. Had blood tests done which shows elevated ESR levels during this time. Been 18 months and no one can tell me what is causing this. I am in agony each month for about a week. Anyone else experienced this?