Unfortunately the reality is that you will have weeks when you stay the same even though you've been 100% on plan. You haven't come to a halt, you just had one week of losing 1lb (which is a good weight loss) followed by a week of sts. You need to look at the bigger picture of how much you have lost as a whole rather than get bogged down in what the scales say on a week by week basis. If you know that you are following the plan, then trust in the fact that you know it works, and move on to the next week. It's also a good idea to have other measures of success to focus on when the scales don't move so why not get out a tape measure and start keeping a record.
womens monthlys can make a big difference, also recheck your portions i know that sounds so simple but you might be suprised! the truth is you havnt put on any weight! it might be time to step up your body magic???
Things aren't coming to a halt. We all have weeks were we STS for no reason. Have you tried varying your diet, I know I tend to eat the same foods all the time but when I mix it up a bit that does make a difference.