I'm pregnant and trying my hardest to maintain my weight, can you leave a suggestion?

I'm 5 months pregnant and woulld only like to gain 5-10 more lbs, my doctor said that would be fine, but it's hard. How can I do this? Is there any healthy "diet" I can do? I know everyone is going to say walk, but I get so bored with that. I used to like kickboxing and really active stuff my dr. said no more, and I don't have a pool otherwise I'd be doing that... any help?