Could front right lower abdominal pain be caused by endometriosos? My GI doesn't think its a GI problem same with my gyno and a colonoscopy was fine.

Best see GP. Sometimes situations like this one require a broader, more holistic perspective, such as what you would get from your pediatrician, internist or gp. Check out your concerns with your generalist.
Endometriosis. The answer is "yes" as endometriosis can cause symptoms almost anywhere in the pelvis or abdomen. The condition is due to uterine tissue getting into the abdomen through the fallopian tubes during menses. If you have already had a colonoscopy, an ultrasound would be the next step, and, if that is negative, the next step would be to have your gyn consider a laparoscopic procedure.
Yes. If your tests were negative so far, your gyn may want to consider a diagnostic laparoscopy to see if you have endometriosis or scar tissue causing the pain.