I am 16 wks pregnant and lately I sometimes have a feeling like food is not going down quickly or like there is an air bubble stuck right below my breast bone. After a while I will pass gas or belch. Is this just normal heartburn, gas, etc.? Sometimes it is uncomfortable, sort of painful, and I will have a slight ache up in my shoulder for a second. I also have the burning and painful feeling in my stomach which I realize probably is heartburn and it gets better when I take Mylanta. The air bubble is new to me, though, and the feeling like the food is not going down quickly or sticking for a second in my upper chest below my throat. I thought symptoms like this wouldn't come until much later when the baby was pressing up.