Same here I get hungry but I have zero appetite, lost 6 pounds since I was 11 weeks now 18, Dr isn't worried so long as I'm not dieting.
I also had no desire to eat in the beginning. Im 17 weeks now and can eat more. Luckally you are gaining. I have lost 6 pounds so far. Just try and eat what you can. As long as baby is growing it will be fine.