It's probably taking longer for them to send you the details due to how busy it is now - we're right on the verge of the deadline and no doubt they're being flooded with apps.
If you're nervous you could always email admissions yourself and ask!
Hey! Give yourself a break!
You were on the right train of thought. Lots of people feel like they did awful and end up doing totally fine. Even if you don't score well, nothing bad is going to happen if you tell UBC that you're retaking the LSAT in January. They only look at your highest score so any lower scores won't even be on their radar.