Hi, I am 26 yrs old i am 5 1 and weight 95 to100 lbs. I am currantly three weeks late on my period. i have had my tubes tied for 5 yrs now. I had a little bit of pink discharge and that was it. i normaly have a 5 to 7 day cycle. I am getting pain on my right side right next to my belly button, and also i get a sharp pain that starts in my vaginal area and shoots to my anus . Say I m in the kitchen and I ll feel it coming on so I have time to brace myself. I ll set down whatever it is i m holding and get ready. I have to cross my legs, bend my knees, hold on to something, clench my body tight, and try to breathe. What could this be?