if they're hard it really sounds like you missed, but you'd know if you did. so i dunno, but pain afterwards is usually pretty common for me anyways. the meth itself stings sometimes towards the end of the shot/for a few minutes afterwards/. there are lots of things that could be causing this. how long ago did you do your shot?
using the same spot a bunch, scratching the inside of your vein, using old needles, plus the fact that you stuck a needle in your arm there are many possibilities, but if you're sure you didn't miss (and usually with meth you know) i wouldn't panic. if it gets worse, or lasts more than a couple of days something might up wrong, but i'm thinkin' you'll be alright.
using the same spot a bunch, scratching the inside of your vein, using old needles, plus the fact that you stuck a needle in your arm there are many possibilities, but if you're sure you didn't miss (and usually with meth you know) i wouldn't panic. if it gets worse, or lasts more than a couple of days something might up wrong, but i'm thinkin' you'll be alright.