Pinning glutes works well for me. I aspirate everytime and it's been pretty uneventful until my last pinning of my last 15 week cycle.
When I inject, it's as smooth as a knife through butter. This last time, I felt an unusual pressure but not pain as the needle broke the skin. I pull back on the plunger expecting to see the few bubbles that appear when aspirating. Instead, blood had entered the syringe. I felt no pain, but realized I hit a vein. Needless to say, I cut that cycle short by one dose. I should've replaced the needle with a new one, but didn't have enough knowledge of pinning a gear/blood cocktail. After all it was my own blood.
If I hadn't aspirated, I may have pinned my gear directly into my vein! I still haven't researched all the info on that topic but I'm glad I'm here to share.