Morning sickness?

Allison • 18 and expecting my first little gummy bear (:
So since aug 3rd, ive gotten a terrible headache and nausea. .. i know its not from eating a lot. But just the idea of food makes me sick. ... when i wake up in the morning it feels like my stomach is being sucked in. I've also noticed that ive lost a lot of weight. .. what can i do?