It's too much of a coincidence to have 2 attacks occur the day before my period these last 2 months. The pain is so intense - center of upper abdomen and entire lower abdomen as well as upper back. Burning, twisting, soreness as if you've been punched so hard making breathing difficult. Both times the pain lasted about 8 hours. The first attack occurred while I was in Vegas and attributed it to poor eating habits and alcohol consumption. The second attack happened the same way, waking me up in the middle of the night with an uncomfortable feeling in the sternum, then quickly escalating to unbearable pain. Some blood tests and an ultrasound later, they have detected stones in my gallbladder. I really hope this is the cause so that I can get a handle on it. I'm terrified about my next period. I'd love to hear about similar experiences and what's worked for other ladies! I'm 43 years old and have never had abnormally painful or irregular periods.