If your shots are favoring the upper left, believe it or not you're flinching. I don't care how many horror movies you watch or how often you skydive, the gun is making you jump when you get the trigger to the break point. It's nothing to be ashamed about. Even long time shooters run into this problem on occasion. The trick is knowing how to recognize it and fix it.
There's any easy way to verify this problem. Have a friend load your magazine and tell him/her to randomly load a couple of snap caps or dummy rounds in with the normal ammo. What this does is creates a scenario where you don't know if the next bullet is actually going to fire or not.
Most times, flinching will be masked by the recoil of the gun itself. In this case, you're going to eventually pull the trigger and nothing will happen when you're actually expecting it to. See the gun jump just then? That's the flinch.
This is an easy problem to fix. Slow down a bit. Concentrate on a slow and smooth trigger pull. That will work out the kinks and you can eventually start speeding up your shots again. Also, it might help to swap to another gun, if you have a spare. When I find myself flinching consistently, I like to swap down to a fun little .22 for a bit. The reduced recoil and sound, combined with super cheap ammo, works that flinch out fast.
