Anything over 300 mg/ml, I would avoid the quads and go with the glutes. Quad shots can be crippling so you will be ok in a few weeks or so.
This is a very individual recommendation, and I must respectfully disagree. My quads handle volumes of 4cc easily, with total concentrations way above what you have listed.
That being said, this sounds like an inflammatory reaction, not infection. NSAIDS, ice, elevation should take care of it.
There are no significant vessels in the upper outer thigh quadrant (typically you're pinning the muscle belly of the tensor fascia lata. A bit more lateral, and a bit lower, and you're pinning the vastus lateralis--there are some larger vessels-known as the "perforators"-in that region, but it's still a relatively safe place to pin).