Last time I did Slimming World it took me a year to lose 2 stone. My weight loss was so slow, I knew I had PCOS but hadn't been officially diagnosed (ie i wouldn't got the doctors even though I knew I had it), now I've been diagnosed and put on the pill the weight seems to be coming off slightly easier than not incredibly fast. I can't really say I have any hints and tips, just persevere it will come off eventually it just takes a while.
Surfhunny to answer your question, everyone gets different symptoms. Some people get heavy period, terrible pains, some get no periods but pains, I had no pain or anything only indication of any problem was that I wasn't getting periods. Get your doctor to send you for an ultrasound, that will tell you if its PCOS or not.