Weigh gain

I know it sounds petty after going through all this to be concerned with weight, but I also gained 18 lbs on the chemo and really want it gone. I am 4 weeks out from my last Taxotere and have been actively exercising (5-6 times a week) and following my Weight Watchers plan, but last week I actually gained weight. How long does it take for your body to get to a good place where the weight can come off? I never did lose my periods and I thought that was a good thing (weight loss wise and I'm er/pr neg).