No, I don' t think you need to worry. I hope you get that appointment soon, so you don't have too long to worry.
I've never heard that excess fluid could be dangerous, just unpleasant. As far as I know a joint that has been over-taxed cushions itself with fluid, which shouldn't recur once it has been drained unless the strain is repeated.
I used to dance professionally, so I do know a little about joints and their reactions.
Hope all goes well.
Do you feel guilty if you have a lie in??
