the idea behind front loading is to start blood accumulation levels and reach what you expect to be sustained peak faster right? So rather than do a doubled up dose, what you do is do a half dose every 3 days instead for the first 3 injects, then you'll see the peak levels sooner and just continue with your normal dosing. At 2 weeks in what you'll mostly get by adding more is side effects.
Overall i'd just as soon see someone use that extra dose at the end of the cycle, to make it a week longer than do the double dose at the front. The difference either way though is so minor, it's simplest just to stick to planned schedule, not mess with it and make observations for the future.