First, I'd recommend you scan your works in. Though I think I know why you don't.
It's usually either a lack of a scanner or the inability to pick things up…
You mentioned you only have a pencil? May I try and urge you to reline things with a pen, if you can?
Some of the lines could be refined, though it doesn't wildly warrant it. If you reline it in pen then you usually make it a lot clearer on the page and fix any minor goofs we all do from time to time.>I work with a Tablet, it took me two more refinements (Lineart over it) to work with it.
In my class-doodles, I found my best images were sketched in Pencil, Lined in Pen and the the pencil removed…>Then I shaded with the pencil…
Your anatomy is great; it's quite amazing. And you're taking on some brilliant poses and positions. I especially like the way you did Pinkie's muzzle, it's a cute style choice.