I started my first pregnancy 12 lbs heavier than this one, and by the end gained 50 lbs. I was eating like a darn pig, and it took a loooooooooooooong time to lose the weight after I gave birth.
So far with this one, I have gained 14 lbs. I printed out a weight gain chart from the web (can't remember which site), but according to it, I am right on track, and my OB hasn't said a word about my weight, so I am not concerned.
Unfortunately, the mmternity clothes I got with my first one are all size large, so most of them are too big for me now. Thank goodness for belly bands.