Joint potential in Scotland?

Hiya, I've read a lot about the upcoming events in Scotland and I would love to come along but do you have to have an official diagnosis or letter from your rheumatologist to join up? I'm still waiting to see a rheumatologist, they have to see me by March but I'm worried the places will fill up by then. I also maybe don't want to take the place of someone who's got long-established disease and maybe needs more support... but I would still love to go and meet people to talk to.