Too much weight gain?!

Kristina
I am a bigger girl, I am 5 foot 2 inches and before I was pregnant I was 181 pounds. I weighed myself today and I'm already 196 so I have gained 15 pounds already! I'm only 25 weeks and feel like I have gained to much. Everything I read says that bigger women shouldn't gain as much. I have only gained in my tummy area but I feel like I'm just unhealthy for my baby!!! I need some advice!