I'm due for my birth control shot on the 24 but i've been having uterus pain on the right side of my uterus i'm not sure what it can be?

Pelvic pain: Pelvic pain is complex as there are several organs in the pelvis. The ovaries, fallopian tubes, uterus, cervix, bladder, appendix, intestines, colon and rectum can all be the source. Pelvic pain requires and examination to help organize the evaluation. Pain in the lower right abdomen is concerning for appendicitis. If pain is severe see a doctor asap.