It's more than likely gas, hormones relax your smooth muscles (intestinal tract) so things move slower so gas bubbles hang around a lot longer making you feel sick and gross. I found peppermint candy helped with this feeling. I also loved making popcicles out of pickle juice... I know it sounds gross but it was one of the few things that gave me complete relief from the all day sickness. Another plus is not taking meds so less biofeedback in your body so it's more natural.