So yes, it is helpful to have a lot of data to determine when your cat's nadir is. Although nadirs can move around a bit. It required a lot of testing to figure this out. If that's not an option during mid-cycles, then another option is to do curves and test every two hours when you're off work. Otherwise, it's good to get tests at different times on different days (+3, +6, +9 etc. on one or two days and maybe +4, +7, etc. on another day). The longer you are testing, the more data you will have and that makes dosing decisions much easier. The longer you go along you also get a better idea of things like how your cat responds to carbs (what you've already been learning) and how long kitty typically takes to clear a bounce.