How much weight should I gain during the first trimester of pregnancy?

I went to the the Dr. today for my check up and I have gained 5 lbs I am 11 weeks and 4 days so almost 12 weeks. Is that to much weight to gain for the first trimester? Or is that normal? How much weight did you gain in the first trimester? And what is the average weight gain during the first trimester? thanks (: