it's not the dosage, it's the concentration that's the problem. Not enough oil per mg of gear. So no matter what dose you pin with test 400, it could be a problem.
If you're not lean, that's also an issue. Quads carry a decent amount of fat, so it's very likely that with such a short pin, you didn't even pin the muscle. I've done subcutaneous injections, and they can hurt like a bitch, even with very low concentration gear. That may be a bigger problem than the test 400 itself. get longer pins, or pin somewhere you don't have much fat.
Also, the quad twitch is normal. I get that a lot while inserting the pin. It's annoying but it's not a problem.