I swap lunch & dinner all the time, depending on my schedule. I work in a restaurant (lucky me!!
) and so if I have to stay and not come home for lunch I have the chef fix me 'dinner,' then I have 'lunch' with my veggies & packet when I get home in the evening. As long as you stay on protocol, you should be fine.
I don't know if the extra exercise will 'mess up' your loss, but it probably won't make it any better! I had a weekend with some extra activity a couple weeks ago, and although I had lost 4 pounds between Monday and Friday, I didn't lose a thing between Friday and my Monday WI!!
Good luck!
Sherilyn