10 weeks pregnant and I haven't gained weight?

You're only 10 weeks, don't worry. I'm a first time mom too and I was the same way. I hated food in my first trimester and actually lost around 7 lbs due to severe morning sickness. I couldn't hold down anything. I didn't really start gaining weight until the end of my second trimester. I'm 3 days overdue now and have only gained around 20 lbs for the entire pregnancy and my baby is perfectly fine. Heartbeat sounds great, she's measuring great. You'll be okay. Don't forget to take your pre-natal vitamins. They're especially important for you in the first trimester. Congratulations and good luck!