You bought the wrong insulin analogue. The N designation means that its intermediate acting, not rapid acting. You want either; R or Log (Huma/Nova), those stay in your blood stream for a petite 5-6 hours, maximal. Humulin N will be running amuck for up to 24 hours, that means you run the risk of going hypo while your sleeping. Plus due to the sensitivity of the polypeptide, you can’t return it once bought. Methinks you shalt be doing some more mental exploration on the topic prior to commencing.