Im on HRT and have a question. I always aspirate, but what if you accidentally do inject right into a vein? What should you do? Call 911 immediately? See how you feel, and if like shit, call 911? Immediately drive to hospital? (possibly passing out at the wheel) I only inject half a cc. Whats my worst case scenario and what should I do if I suddenly realize I just injected into a blood vessel because I suddenly feel weird? What are the symptoms of injecting into a blood vessel anyway? Will it be way obvious and IMMEDIATE???