I injected my left pec last Thursday and it is absolutely killing me. It's not like any other injection pain I've ever felt. I can't stretch my left pec at all, that means I can't work out any muscle besides my legs. I can't lift up my left arm all the way either from the pain I feel in my chest. I don't understand what's causing this, cause the day before I injected my left pec I injected my right pec and nothing happened other than one day of soreness.