Gaining Weight

Ok. Since I got my BFP I've cut back tremendously with what I eat. Hardly any sweets &NO sodas at all, but for some reason I'm gaining 1.5 lbs a weeks. I'm only 5 weeks 1 day and with my last pregnancy I gained 65lbs. I'm about 15lbs heavier then I was at 37 weeks with baby #1. Is anyone else having this problem? I don't wanna just eat one meal a day.