I almost have to laugh reading these since I have already gained 18 pounds (yes I said 18 POUNDS!) at 12 weeks. I gained 70 total with dd. I'm not a heavy person (I average 120) but for some reason gain lots during pg. I feel awful unless I am eating. I'm very dissappointed because i didn't want to have a repeat of last time, so I'm going to see a dietitian in 2 weeks. My doc said that we'll work on the weight thing once I get through the miserable morning sickness. The prob with dd was that after I started feeling better, I didn't modify my diet and ate like a pig. Oh, I should mention that I started that pregnancy underweight at 105, so the doc started counting my weight gain once I reached 125 (6 weeks). I delivered by csection at 175 lbs.
Don't freak out too much about your weight. I was back down to 125 within 5 months-- breastfeeding is the key!!! That said, the weight gain took a terrible toll on me physically - I had lots of joint pain and of course was terribly uncomfortable. I'm trying to have some willpower this time - starting now!