I would say go for it! I did the same thing, because at least for me it will also be my first, and realistically, if anything goes wrong, there won't be another test until later, by which time law school admissions will be a lot harder. So I would say if you have to money for both registration fees, do it, because best case and you really well and cancel taking it a second time. Or worst case, and you oversleep and miss the October one, you can still take the November one and be on time to apply by the end of the year!