Have you even taken a grav reading yet through all these discussions?
That would answer your question about your beer instantly
and have given you piece of mind, instead of using a flawed method like looking at an airlock as a guide.
Fermentation is not always "dynamic," just because you don't SEE anything happenning, doesn't mean that anything's wrong, and also doesn't mean that the yeast are still not working dilligantly away, doing what they've been doing for over 4,000 years....
The only way to truly know what is going on in your fermenter is with your hydrometer.
Like I said here in my blog, which I encourage you to read, Think evaluation before action
you sure as HELL wouldn't want a doctor to start cutting on you unless he used the proper diagnostic instuments like x-rays first, right? You wouldn't want him to just take a look in your eyes briefly and say "I'm cutting into your chest first thing in the morning." You would want them to use the right diagnostic tools
before the slice and dice, right? You'd cry malpractice, I would hope, if they didn't say they were sending you for an MRI and other things before going in.....
Thinking about pitching more yeast before taking a hydrometer reading after waiting an intial 72 hours, is the same thing....thinking about a "cure" before we even know if the beer is even "sick."
Nothing I have read of your info leads me to believe that there is anything wrong or "different" with your beer than any of the other nervous first time brewers who post on here.
The cure for that is to take a hydrometer reading, pure and simple.
It's really really hard for this stuff NOT to turn out.