Nuvaring and GI Problems!

I stared the nuvaring back in January. Shortly after I developed stomach issues including: constipation, pain after eating, stomach swelling/bloating, sulfur burps (rotten eggs)... I've had my gallbladder checked and it's fine. I've had a colonoscopy and an upper GI and they show nothing. I feel that my nuva ring is the problem but doctor doesn't seen too worried. Anyone else have/had this problem?