When you scan the Novopen with your phone, each dose is recorded separately so, if you have done a couple of tests before injecting, it might show on your Librelink app as 1 unit, 1.5 units, 5 units. If you then go into the logbook on the app and select the relevant dose, you can edit between an injected dose and a flow check. (And, yes, AFAIK you should check the flow before each injection.)