Hey there, I've just been reading through your thread. I'm so sorry you're feeling so low about things at the moment.
I can't offer any advice on your PCOS or why you haven't had a period since coming off the pill.
But do you have a doctor you can talk to? I know it can take time for the body to settle down after stopping the pill but I've no idea how long it can take. It probably wouldn't do any harm to ring the doctor to see if this is normal, or if there's anything you can do to bring on your period. Don't let it be going around in your head stressing you when a doctor might be able to give you a simple explanation.
And as for having a baby, nobody knows what the future holds. You still have plenty of time to get pregnant so please don't lost hope. I have a friend who always wanted to have kids. That's all she ever talked about. By the time she was 35 she had no kids and no boyfriend but refused to give up hope. She met someone when she was 37 and was pregnant a year later. She had twins and she will be 40 this year. So there's always hope.
I'm not sure what your neck scan is about tomorrow but the best of luck with it. I hope it goes well xx