Yes its more common then u think. I was the same way with my baby girl and lost 15lbs and never gained....never got sick jus so nauseous and couldn't really eat and when I did eat I always got full fast. My doctor said it was fine as long as I took my prenatals and jus try to eat when I could. And now I have a healthy 1 month old baby girl:) oh and my sister is pregnant with her fourth and all her pregnancies she always lost weight and not gained! So jus try ur best and eat when u can, good luck!
I have the same problem. I'm 13w5d and I'm 5'6 128 I've only lost 4lbs but it has me worried. I eat like a cow and I've only puked maybe 3 times.