I had my first official weigh in last Thursday and lost 6lbs.
During that week I worked out at the gym 3 times, went to a pilates class and climbed mount snowdon.
So I really think exercise helped a lot.
As for water retention before WI, I weighed in at 10am on Thursday - I went to the gym straight before WI so I can't see that I have that problem.
Since last WI I have been to the gym twice, and did 2 Zumba classes. Got Aquafit tonight, Pilates on Wednesday and hopefully a couple more gym sessions before then.
Fingers crossed I have a loss again this week.