The only way of finding out whether your basal is correctly set is the fasting test! Test every hour to see what is happening... Do remember if you go too high or hypo then you need to abort the fasting a take correct accordanly..
It's easier if you split your fasting test in sectors of the day, morning runing to just past dinner, overnight and then have brekkie, miss dinner and then do the afternoon can do it any order you want, over night basal testing can been done on one night if you fancy being disturb every hour, or you can do one night testing up every hour up to about 1am, then the following night start at 1am through to morning, or may be one night test every other hour and the next on the other hour you missed.. but remember for nigth testing have carbs that don't linger in the system such as pasta or a high fat content meal that slows adsorption.. And if you are doing testing over several night your bedtime BG should be pretty similar, and you ideally same sort of routine during the day ect..
Don't forget if your basal is out, you will need to reject your insulin to carb ratio's for the quick acting insulin as you may have been over or under correcting for the missing/over dose of basal insulin!