Hope you get a good result to cheer you up today. Don't panic too soon - it's very unlikely that following the plan you will not lose weight, even if it is a bit slower than for some people. If things don't go well feel free to post on here and I'm sure people will have helpful suggestions as to where it might've gone wrong. What did you do between 1st Dec and joining SW that made you lose 7lb? Well done whatever it was. Also remember that if you have a big loss your body can rebel a bit and it takes a while to adjust to new lifestyles.
I've heard some people with PCOS say that doing Red days helps as they cut down on carbs as well, but for me I don't think that would work because the PCOS means I crave carbs/sugar and I would not stick to it.
Drs have told me that losing 10% of your body weight is thought to help a lot with PCOS symptoms. So when you get to Club 10 you should def be seeing improvement, and it's great that you're noticing skin changes already. Just shows it's a healthier diet even if you don't see weight loss immediately.