Girls, has anyone experienced this: you eat normally, but after 20–30 …

Girls, has anyone experienced this: you eat normally, but after 20–30 minutes you feel very hungry, yet at the same time you have the feeling that your stomach is full. I had this during my morning sickness — back then, as soon as I sat down to eat something it all came back up. And today I have that same feeling: I ate normally, but I want to eat again, even though my stomach is full, there's even a heaviness.