I Am 31 Weeks Pregnant And I Am Having Burps

I am 31 weeks pregnant and I am having burps that smell and taste like rotton eggs. This started today, and Im not sure what is causing it but I discovered that I could' nt release bowel movement today as well. I drink soda and eat a lot of chicken and Turkey product.could these foods and drink be causing this change?, and how can I make the burps go away?