Green diarrhea

Bree • 25 years old. Madly in love with my king 💘. Have one healthy baby boy who just turned two and one on the way! 🍼👶 2 angels in heaven 👼👼.
Ever since my son got his two month vaccinations he's had green watery diarrhea. That was over a month ago. They're running stool tests now but they always say he looks great. I just don't think it's a coincidence. Has anyone had this problem? He is on formula. Thank you