When was the last time you've been to you OB? Maybe you are mistaking the movement for gas.
With my first I didn't feel him move until I was a little over 22 weeks my second I felt at 19 1/2 weeks but with this one my 3rd pregnancy I started feeling the baby move at 14 1/2 weeks
I am 20 weeks 5days with my 3rd.... I felt movement a couple of times - but I am thin and this is my third.. with that being said - it is normal to not feel the baby move for a couple more weeks.. She has moved only a little since Saturday and I know it is her and not gas because I have already had two little ones... if it were not for them I would pass it off as gas... I am not hungry either... I am forcing myself to eat as I feel full all the time.. I think you are okay - but check with your dr and maybe they can bring you in for a heartbeat check.... which is always nice to hear. Good Luck