I've noticed some chatter around regarding the fact that the oils have gotten so thin that it's sometimes hard to be patient and people end up pushing the Test in too fast which can lead to a delayed bruising and a bit of a bump/lump a couple days later. As well what @Jetpilot said about being careful not to move the needle angle at all. What's on the inside isn't nearly so tough as what's on the outside and it's pretty easy to cause a minor hematoma if you happen to nik or bother a blood vessel. I know I will get a trickle of blood, the odd time, when I pin in my delt but it's only ever the right one, dunno why.
The pain moving the shoulder sounds almost like you might have pinned too high and gotten into the bursa? The deltoid and the bursa overlap a little from what i recall of what the inside there looks like and it doesn't take a whole lot to aggravate the bursa, that I know from previous personal experience, not pinning just general bursitis stuff. Taking it easy and some ice & anti-inflammatory should fix that right up if that's what it is.