Relax.

As pointed out above youre over thinking this. This wont help the shakeyness either.

Also as pointed out above, you should rotate your injection sites. Also, often when you inject a virgin muscle the first one or two times it can be very stiff. I injected today (on week 5/6) and if i think about it hard, i can feel a little discomfort, perhaps stiffness etc. But, you get used to it, so stop over thinking it. Unless it looks like its infected, you will be fine.

Oh, and perhaps its not a good idea to inject yourself in the glutes before working legs.

And glad to hear you picked up some longer pins.