Loss of Appetite?

Hello everyone. I'm 15 weeks and 2 days pregnant and I'm still experiencing a loss of appetite. I eat about half as much as I did before becoming pregnant and have lost close to 15 pounds since the beginning. It is also still difficult for me to find things that sound appetizing and I've yet to crave something. Is anyone else still experiencing these symptoms after 15 weeks? Everything seems normal and healthy other than that and I haven't had a bad report from my doctor. I've also been told some mothers experience this throughout their whole pregnancy and continually lose weight while the baby remains healthy and gains it's normal weight. Any information or advice would be greatly appreciated!