Its pretty common for women to lose their appetite during the begining stages of pregnancy. I myself lost my appetite to many foods along with constant nausea. I lost a bit of weight not much but now that I am in my 2nd tri the sickness is gone and I feel like eating again which is great. Make sure you are taking your prenatals to atleast give you as many nutrients as you can while your going through this. Try eating light foods in small amounts more frequently throughout the day. I found that fruits helped me a lot. I hope you feel better soon!
I have a friend who lost 15 lbs (in her first trimester) with her first pregnancy - was sick as a dog but went on to have a healthy son! Your appetite will return!
Yay, so great you got to hear the HB. I also loose weight quickly in the first trimester. I will gain it back in the 2nd and 3rd tho. :)