Well I'm 22 weeks pregnant today! I am having the SAME problem. The last time I was at the doctor's a month ago I got yelled at because I still haven't gained a pound. I think I'm gaining weight now though. My first trimester I felt sick ALL the time. Prettymuch right as soon as I hit the second it totally went away. I think it also might be because when I started out I weighed about 20lbs more than I usually do.
When I had my son I gained everything by the book. But I was really healthy back then and I only weighed 130lbs. I gained exactly 1-2lbs a month then more in the end. I also wasn't sick at all with him and only threw up once in the 3rd trimester.
Anyways, don't worry about it too much. Just take your pills and don't let yourself become hungry, that means don't skip meals. As long as you're eating and the stuff you put into your mouth is good for you that's what matters. I've known people to LOSE weight with their pregnancies and everything turned out fine.
And if you have to treat yourself to MAKE yourself eat then do it. There were times when I didn't feel like eating, so I would drive out to KFC or Subway and order my favorite takeout from there because I KNEW I would eat it all no matter how sick I felt. It's one of those small sacrifices to make for your baby
