Gaining to much wait.

Brittany
I'm 10 weeks and I'm gaining way more wait then I should. The week I officially found out I was pregnant I weighed myself at 135. Four weeks later at my first ob appointment for my prenatal I weighed 147. Last night at work I weighed myself at 153. I don't understand why I'm gaining so much wait. I'm completely stopped eating snacks and junk food. Stopped with all the fatty t.v. dinners (easiest thing to pack for lunch at work) kicked out all soda. I even stopped salting all my foods(i used to eat a lot of salt). I'm eating three small main meals a day with a few snacks if I get hungry. But they're always just fruit. My ob told me I should only gain between 15-25 lbs through my entire pregnancy. It seems like I'm going to gain a lot more then what's recommended. Has this happened to anyone even with eating as healthy as it gets???