Hi, I was wondering if I am at risk of contracting hiv, I've been attending to a doctor for varicose veins, so the inyections are performed directly in the vein. Every time I go in he already has the syringe prepared, I only see him change the needle. It's an instrument of two syringes conected and he exchanges the liquid from one to another to make some foam, and then he pinches me. When I leave he puts the syringe with the needle on the table and that's all I can see. In case he changes the needle but not the syringe am I at risk for hiv?