Sorry to hear about your redundancy stuntnun, it sounds like you are being treated really badly by the company. I hope you end up very good payout at the end at least.
My friend was in a similar position to you - 20 or so weeks pregnant, she got promoted, a communication went round to the whole company saying what a great job she was doing and then about two weeks later she was put at risk. She had a month or so to find another role but it was never going to happen.
Luckily one of her good friends is an employment lawyer and was able to help her put a case together which helped her argue for an ok redundancy payment.
Her friend did say that whilst pregnant you don't have any more rights than anyone else (although you do when you go on maternity leave) but they do have to be v v careful that they have selected you for the right reasons and not because you are pregnant.
Issy, sorry to hear about you needing crutches. Are you likely to need them for the rest of the pregnancy or is there a chance that the physio will help improve the PGP?