Do I Need To ....

Soooo my last appointment I was told I gained 10lbs in a month, I was 25 weeks. Well my doc told me to just walk more, eat more proteins and drink more water... I've been doing the best I can, as I wake up at 2 in the afternoon it's hard to be on a strict schedule. My question is, do I need to diet at all, watch what I eat more, no sweets and workout??? I may be over thinking it but I really don't wanna gain another 10 each month till I'm due. (Currently 26 almost 27 weeks)