I have been pooping green for almost 3 weeks.. only having about three or four brown poop in that time.

Don't worry: The color of your bowel movements usually don't mean anything (unless its bloody or dark black). Its usually related to what your eating/drinking and what meds your taking. I wouldn't worry too much about it unless you develope symptoms (diarrhea, constipation, abdominal pain, nasea, etc). In that case see your doctor.

Poop: May be diet or med related but you should get a stool culture with your doctor

Green stool: The green is bile that is traveling too quickly through your intestine for the bacteria to turn it brown. Conditions that may cause it (diarrhea) include: laxative use, food poisoning, celiac disease, C.diff diarrhea, malabsorption, IBD, infectious diarrhea, alcohol abuse.excess iron supplements or gall stones. Without any symptoms or medical or social hx, cant suggest a cause in you.