Calories?

Before becoming pregnant I kept my weight around 120-122 by eating anywhere from 1,200-1,500 calories each day. (I am only 5'1" so even at this weight I could still afford to lose a couple pounds.)

I am 6 weeks pregnant and eating well over 2,000 calories because I am so hungry and get dizzy if I don't eat every few hours. I am already up to 125 and nervous about gaining to much weight. Does anyone follow a diet or calorie guide??