so i haven't had access to any clean needles, therefore i've been rotating these 3 that i do have and they're getting pretty dull now with 6 or 7 uses. i missed on both my arms, so i don't really have many options except for the vein on the inside of my lower leg (next to or along my shin). i've never shot up in the leg before, so is it going to be a lot harder to penetrate the skin down and there actually register in a vein as opposed to registering in the arm? also i want to slide the needle in so that the point is facing upwards towards my heart (same as the arm), correct? btw, i'm shooting BTH.