Lost weight this pregnancy?

Amanda • Wife to my best friend❤️2/3/11. Mommy to two beautiful boys💕2/25/11 && 8/2/13. Mommy to three Angel Babies👼🏼👼🏼👼🏼
Has anyone lost a significant an mouth of weight during pregnancy? I'm not a small girl by no means, but this baby girl has had me sick since week 4 and I'm 20w. I've lost 12lbs since my initial OB  appointment. My doctor didn't seem concerned until last appointment because I was dehydrated and hadn't been keeping much down. He prescribed me Zofran but long story short I won't take that and can't the alternatives to keep food down. Anyway, when should I be concerned?  I feel like my belly is pretty big and she's thriving. The baby takes what she needs right?