For 2 wks, pms-like cramps in lower right side with back and leg pain on that side. off & on, worse throughout day, worse when sitting. what is this?

Several Possible: Abdominal cramps have many reasons, However, when they are localized to the pelvis and one side, then the concern increases about an ovarian cyst or other pelvic issues. A gyn exam and vaginal ultrasound is very helpful to eliminate problems that need to be treated and/or followed. Seeing a GYN doctor if your symptoms persist or get worse is a good idea.