Using a Gestational calendar,if the first day of your last period was June 21 and you know you concieved on July 5, you would be 40 weeks on March 27.
Have you had any abdominal surgery? I have had the same type of pain and it was diagnosed as scar tissue that had adhered itself from the abdominal wall to the muscular tissue. This will not show up in any scans or xrays. Good Luck!