I Am A Woman. Age 42. All Past PAP Up

I am a woman. Age 42. All past PAP up to date and all came back good. No issues. Past two years I get a pain that is in my abdomen that commences abruptly. It is a pain that spreads through my whole stomach area and can feel the pain radiating up to my neck and face. It always seems to happen near or after my menstrual cycle. It is happening once a month now. It is the kind of pain that makes me stop everything I am doing. I have to focus on meditating and breathing and lifting my arms up to wait for the pain to go. I have IBS but this is not an IBS related hurt. It is not menstrual cramps. The "spasm" lasts a while...then dissipates....what is this??