Sharp Stabbing Pain

I've had pain shooting from my cervix up into my abdomen for about a year now. It's not constant, but happens about twice a week and can bring me to my knees. It happens with no warning and only last for a few seconds. What in the world could this be? My Pap smears and STD testing have all come back clean. I know this isn't normal but my current doctor blows me off when I mention it.